Internal combustion engine and working cycle

ABSTRACT

Invention of deriving mechanical work from a combustion gas in internal combustion engines and reciprocating internal combustion engines for carrying out the method, including methods and apparatuses for managing combustion charge densities, temperatures, pressures and turbulence in order to produce a true mastery within the power cylinder in order to increase fuel economy, power, and torque while minimizing polluting emissions. Methods and apparatuses for, among others, (i) producing an air charge, (ii) controlling the temperature, density and pressure of the air charge, (iii) transferring the air charge to a power cylinder of the engine such that an air charge having a weight and density selected from a range of weight and density levels ranging from below atmospheric weight and density to heavier-than-atmospheric weight and density is introduced into the power cylinder, and (iv) then compressing the air charge at a lower-than-normal compression ratio.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 09/632,739,filed Aug. 4, 2000; which is a continuation of application Ser. No.08/863,103, filed May 23, 1997, now U.S. Pat. No. 6,279,550; whichapplication claims the benefit of provisional application Nos.60/022,102, filed Jul. 17, 1996; 60/023,460, filed Aug. 6, 1996;60/029,260, filed Oct. 25, 1996; and 60/040,630, filed Mar. 7, 1997, andwhich is a continuation-in-part of application Ser. No. 08/841,488,filed Apr. 23, 1997, now abandoned.

INCORPORATION BY REFERENCE

The specification of application no. 08/863,103, filed May 23, 1997(U.S. Pat. No. 6,279,550) is incorporated herein in its entirety, bythis reference.

BACKGROUND OF THE INVENTION

It is well known that as the expansion ratio of an internal combustionengine is increased, more energy is extracted from the combustion gasesand converted to kinetic energy and the thermodynamic efficiency of theengine increases. It is further understood that increasing air chargedensity increases both power and fuel economy due to furtherthermodynamic improvements. The objectives for an efficient engine areto provide a high-density charge, begin combustion at maximum densityand then expand the gases as far as possible against a piston.

Conventional engines have the same compression and expansion ratios, theformer being limited in spark-ignited engines by the octane rating ofthe fuel used. Furthermore, since in these engines the exploded gasescan be expanded only to the extent of the compression ratio of theengine, there is generally substantial heat and pressure in theexploding cylinder which is dumped into the atmosphere at the time theexhaust valve opens resulting in a waste of energy and producingunnecessarily high polluting emissions.

Many attempts have been made to reduce the compression ratio and toextend the expansion process in internal combustion engines to increasetheir thermodynamic efficiency, the most notable one being the “Miller”Cycle engine, developed in 1947.

Unlike a conventional 4-stroke cycle engine, where the compression ratioequals the expansion ratio in any given combustion cycle, the MillerCycle engine is a variant, in that the parity is altered intentionally.The Miller Cycle uses an ancillary compressor to supply an air charge,introducing the charge on the intake stroke of the piston and thenclosing the intake valve before the piston reaches the end of the inletstroke. From this point the gases in the cylinder are expanded to themaximum cylinder volume and then compressed from that point as in thenormal cycle. The compression ratio is then established by the volume ofthe cylinder at the point that the inlet valve closed, being divided bythe volume of the combustion chamber. On the compression stroke, noactual compression starts until the piston reaches the point the intakevalve closed during the intake stroke, thus producing alower-than-normal compression ratio. The expansion ratio is calculatedby dividing the swept volume of the cylinder by the volume of thecombustion chamber, resulting in a more-complete-expansion, since theexpansion ratio is greater than the compression ratio of the engine.

In the 2-stroke engine the Miller Cycle holds the exhaust valve openthrough the first 20% or so of the compression stroke in order to reducethe compression ratio of the engine. In this case the expansion ratio isprobably still lower than the compression ratio since the expansionratio is never as large as the compression ratio in conventional2-stroke engines.

The advantage of this cycle is the possibility of obtaining anefficiency higher than could be obtained with an expansion ratio equalto the compression ratio. The disadvantage is that the Miller Cycle hasa mean effective pressure 10 lower than the conventional arrangementwith the same maximum pressure, but with no appreciable improvements inemissions characteristics.

The Miller Cycle is practical for engines that are not frequentlyoperated at light-loads, because at light-load operation the meancylinder pressure during the expansion stroke tends to be near to, oreven lower than, the friction mean pressure. Under such circumstancesthe more-complete-expansion portion of the cycle may involve a net lossrather than a gain in efficiency.

This type of engine may be used to advantage where maximum cylinderpressure is limited by detonation or stress considerations and where asacrifice of specific output is permissible in order to achieve the bestpossible fuel economy. The cycle is suitable only for engines thatoperate most of the time under conditions of high mechanical efficiency,that is, at relatively low piston speeds and near full load.

SUMMARY OF THE INVENTION

Briefly described, the present invention comprises an internalcombustion engine system (including methods and apparatuses) formanaging combustion charge densities, temperatures, pressures andturbulence in order to produce a true mastery within the power cylinderin order to increase fuel economy, power, and torque while minimizingpolluting emissions. In its preferred embodiments, the method includesthe steps of (i) producing an air charge, (ii) controlling thetemperature, density and pressure of the air charge, (iii) transferringthe air charge to a power cylinder of the engine such that an air chargehaving a weight and density selected from a range of weight and densitylevels ranging from atmospheric weight and density to aheavier-than-atmospheric weight and density is introduced into the powercylinder, and (iv) then compressing the air charge at alower-than-normal compression ratio, (v) causing a pre-determinedquantity of charge-air and fuel to produce a combustible mixture, (vi)causing the mixture to be ignited within the power cylinder, and (vii)allowing the combustion gas to expand against a piston operable in thepower cylinder with the expansion ratio of the power cylinder beingsubstantially greater than the compression ratio of the power cylindersof the engine. In addition to other advantages, the invented method iscapable of producing mean effective [cylinder] pressures (”mep⇄) in arange ranging from lower-than-normal to higher-than-normal. In thepreferred embodiments, the mean effective cylinder pressure isselectively variable (and selectively varied) throughout the mentionedrange during the operation of the engine. In an alternate embodimentrelated to constant speed-constant load operation, the mean effectivecylinder pressure is selected from the range and the engine isconfigured, in accordance with the present invention, such that the meaneffective cylinder pressure range is limited, being varied only in theamount required for producing the power, torque and speed of the dutycycle for which the engine is designed.

In its preferred embodiments, the apparatus of the present inventionprovides a reciprocating internal combustion engine with at least oneancillary compressor for compressing an air charge, an intercoolerthrough which the compressed air can be directed for cooling, powercylinders in which the combustion gas is ignited and expanded, a pistonoperable in each power cylinder and connected to a crankshaft by aconnecting link for rotating the crankshaft in response to reciprocationof each piston, a transfer conduit communicating the compressor outletto a control valve and to the intercooler, a transfer manifoldcommunicating the intercooler with the power cylinders through whichmanifold he compressed charge is transferred to enter the powercylinders, an intake valve controlling admission of the compressedcharge from the transfer manifold to said power cylinders, and anexhaust valve controlling discharge of the exhaust gases from said powercylinders. For the 4-stroke engine of this invention, the intake valvesof the power cylinders are timed to operate such that charge air whichis equal to or heavier than normal can be maintained within the transfermanifold when required and introduced into the power cylinder during theintake stroke with the intake valve closing at a point substantiallybefore piston bottom dead center position or, alternatively, with theintake valve closing at some point during the compression stroke, toprovide a low compression ratio. In some designs another intake valvecan open and close quickly after the piston has reached the point thefirst intake valve closed in order to inject a temperature adjusted highpressure secondary air charge still at such a time that the compressionratio of the engine will be less than the expansion ratio, and so thatignition can commence at substantially maximum charge density. The2-stroke engine of this invention differs in that the intake valves ofthe power cylinders are timed to operate such that an air charge ismaintained within the transfer manifold and introduced into the powercylinder during the scavenging-compression (the 2nd) stroke at such atime that the power cylinder has been scavenged by low pressure air andthe exhaust valve has closed, establishing that the compression ratio ofthe engine will be less than the expansion ratio of the power cylinders.Means are provided for causing fuel to be mixed with the air charge toproduce a combustible gas, the combustion chambers of the powercylinders are sized with respect to the displaced volume of the powercylinder such that the exploded combustion gas can be expanded to avolume substantially greater than the compression ratio of the powercylinder of the engine.

The chief advantages of the present invention over existing internalcombustion engines are that it provides a compression ratio lower thanthe expansion ratio of the engine, and provides, selectively, a meaneffective cylinder pressure higher than the conventional enginearrangement with the same or lower maximum cylinder pressure than thatof prior art engines.

This allows greater fuel economy, and production of greater power andtorque at all RPM, with low polluting emissions. Because chargedensities, temperatures and pressures are managed, light-load operationis practical even for extended periods, with no sacrifice of fueleconomy. The new working cycle is applicable to 2-stroke or 4-strokeengines, both spark-ignited and compression-ignited. For spark-ignitedengines the weight of the charge can be greatly increased without theusual problems of high peak temperatures and pressures with the usualattendant problem of combustion detonation and pre-ignition. Forcompression-ignited engines, the heavier, cooler, more turbulent chargeprovides low peak cylinder pressure for a given expansion ratio andallows richer, smoke-limited air-fuel ratio giving increased power withlower particulate and NO_(x) emissions. Compression work is reduced dueto reduced heat transfer during the compression process. Enginedurability is improved because of an overall cooler working cycle and acooler than normal exhaust. It also provides a means of regenerativebraking for storing energy for subsequent positive power cycles withoutcompression work and for transient or “burst” power which furtherincreases the overall efficiency of the engine.

All of the objects, features and advantages of the present inventioncannot be briefly stated in this summary, but will be understood byreference to the following specifications and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of internal combustion engines according to the inventionwill now be described, by way of example, with reference to theaccompanying drawings, in which:

FIG. 1 is a perspective view (with portions in cross-section) of thecylinder block and head of a six cylinder internal combustion engineoperating in a 4-stroke cycle, and representing a first embodiment ofthe apparatus of the present invention from which a first method ofoperation can be performed and will be described. Among its othercomponents, this embodiment is seen as having one ancillary compressor,a cooling system and valves to control charge pressures, density andtemperature.

FIG. 2 is a schematic drawing of a six cylinder internal combustionengine, similar to the engine of FIG. 1, operating in a 4-stroke cycle,and representing a second embodiment of the apparatus of the presentinvention from which a second method of operation can be performed andwill be described. Among its other components, this embodiment is seenas having two compressors, three intercoolers, four control valves, dualair paths for both the primary and the ancillary compressors, dualmanifolds and showing a means of controlling charge-air pressures,density and temperatures.

FIG. 3 is a perspective view (with portions in cross-section) of thecylinder block and head of a six cylinder internal combustion engineoperating in a 4-stroke cycle, and representing a third embodiment ofthe apparatus of the present invention from which a third method ofoperation can be performed and will be described.

FIG. 4 is a perspective view (with portions in cross-section) of thecylinder block and head of a six cylinder internal combustion engineoperating in a 4-stroke cycle, and representing a fourth embodiment ofthe apparatus of the present invention from which a fourth method ofoperation can be performed and will be described. Among its othercomponents, this embodiment is seen as having an ancillary compressor,with two charge-air intake ducts and dual intake air routes, one ofwhich is low pressure and one which is high pressure, and both leadingto the same power cylinder, a cooling system and valves for controllingcharge-air pressures, density and temperature and an ancillaryatmospheric air intake system.

FIG. 4-B is a perspective view (with portions in cross-section) of anengine similar to the engine of FIG. 4 with the exception that there isonly one atmospheric air intake which supplies charge-air to the powercylinders at two different pressure levels.

FIG. 4-C is a schematic view of an exhaust and an air intake system ofan engine showing a means of re-burning exhaust gases in order to reducepolluting emissions.

FIG. 5 is a perspective view (with portions in cross-section) of thecylinder block and head of a six cylinder internal combustion engineoperating in a 4-stroke cycle, and representing a fifth embodiment ofthe apparatus of the present invention from which a fifth method ofoperation can be performed and will be described. Among its othercomponents, this embodiment is seen as having one atmospheric airintake, an ancillary compressor with two charge-air routes, one of whichis low pressure and which has two optional routes, and one which is highpressure, both leading to the same power cylinder, and control valvingmeans and air coolers for varying charge densities, pressures andtemperatures in the combustion chamber of the engine.

FIG. 6 is a part sectional view through one power cylinder of the4-stroke engine of FIG. 4, FIG. 4-B, FIG. 5, FIG. 7 or FIG. 33 at theintake valves showing an alternative method (adaptable to otherembodiments of the present invention) of preventing charge-air back flowand of automatically adjusting the charge pressure-ratio of the cylinderduring the air charging process.

FIG. 7 is a schematic drawing of a six cylinder, 4-stroke enginerepresenting yet another embodiment of the apparatus of the presentinvention, from which yet another method of operation can be performedand will be described, and depicting three alternative systems (two inphantom lines) of inducting a low pressure primary air charge. Among itsother components, this embodiment is seen as having three air coolersand dual manifolds and the means of controlling the temperature, densityand pressure of the charge by an engine control module and by valvingvariations.

FIG. 8 is a perspective view (with portions in cross-section) of thecylinder block and head of a six cylinder internal combustion engine,operating in a 2-stroke cycle, and representing a first 2-strokeembodiment of the apparatus of the present invention from which stillanother method of operation can be performed and will be described.Among its other components, this embodiment is seen as having a primaryand an ancillary compressor, a cooling system and conduits and valves toadjust charge density, temperature and pressure according to theinvention.

FIG. 9 is a perspective view (with portions in cross-section) of thecylinder block and head of a six cylinder internal combustion engineoperating in a 2-stroke cycle, and representing a second 2-strokeembodiment of the apparatus of the present invention from which stillanother method of operation of can be performed and will be described.Among its other components, this embodiment is seen as having oneatmospheric air intake, a primary and an ancillary compressor, with twocharge-air routes, one of which is low pressure which has alternateroutes, and one of which is high pressure, and both leading to the samepower cylinder, and control valving means and air coolers for varyingcharge densities, pressures and temperatures in the combustion chamberof the engine.

FIG. 9-B is a schematic drawing of a six cylinder, 2-stroke enginerepresenting yet another embodiment of the apparatus of the presentinvention, from which yet another method of operation can be performedand will be described, and depicting two alternative systems (one inphantom lines) of inducting a low pressure primary air charge. Among itsother components, this embodiment is seen as having three air coolersand dual manifolds and the means of controlling the temperature, densityand pressure of the charge by an engine control module and by valvingvariations.

FIG. 10 is a part sectional view through one power cylinder of the2-stroke engine of FIG. 9, at the intake valves, showing an alternativemethod (adaptable to other embodiments of the present invention) ofpreventing charge-air back flow during high pressure air charging andshowing a pressure balanced valve having a pumped oil/air coolingsystem.

FIG. 11 is a perspective view (with portions in cross-section) of thecylinder block and head of a six cylinder internal combustion engineoperating in a 2-stroke cycle, and representing a third 2-strokeembodiment of the apparatus of the present invention from which stillanother method of operation of can be performed and will be described.Among its other components, this embodiment is seen as having a primaryand an ancillary compressor, a cooling system and conduits and valves toadjust charge density, temperature and pressure and having a single airintake runner for each power cylinder with at least two intake valvesarranged in such a manner that one intake valve can operate with timingindependent of the other intake valve.

FIG. 12 is a pressure-volume diagram comparing the cycle of the engineof this invention with that of a high-speed diesel engine.

FIG. 13 is a chart showing improvements possible in the engine of thisinvention in effective compression ratios, peak temperatures andpressures, charge densities and expansion ratios, in comparison with apopular heavy-duty 2-stroke diesel engine.

FIG. 14 is a chart showing improvements possible in the engine of thisinvention in effective compression ratios, peak temperatures andpressures, charge densities and expansion ratios, in comparison with apopular heavy-duty, 4-stroke diesel engine.

FIG. 15 is a schematic drawing of suggested operating parameters foroperation of the engines, both 2-stroke and 4-stroke, of FIGS. 5-7 andFIGS. 9-10 showing dual intercoolers for the main compressor, a singleintercooler for a secondary compressor and a control system and valvesfor selecting different charge-air paths for light-load operations, anddepicting (one in phantom lines) two alternative systems of inducting alow pressure primary air charge.

FIG. 16 shows suggested valve positions for supplying manifolds 13 and14 with an air charge optimum for medium-load operation for the enginesof FIGS. 5-7 and FIGS. 9-10. For medium-load operation the shutter valve5 of compressor 2 would be closed and the air bypass valve 6 would beopen to pass the air charge uncooled without compression to the intakeof compressor 1 where closed shutter valve 3 and closed air bypass valve4 directs the air charge now compressed by compressor 1 past theintercoolers to manifolds 13 and 14 with the air compressed and heatedby compressor 1, for medium-load operation.

FIG. 17 shows a suggested scenario for providing the engines of FIGS.5-7 and FIGS. 9-10 with a high density air charge for heavy duty, highpower output operation. FIG. 17 shows all shutter valves 5 and 3 and allair bypass valves 6 and 4 closed completely so that the primary stage ofcompression is operative and a second stage of compression is operativeand the entire air charge, with the exception of any going throughconduit 32 to intake valve 16-B, is being passed through theintercoolers 10, 11 and 12 to produce a very high density air charge tomanifolds 13 and 14 and to the engines power cylinders for heavy-loadoperation.

FIG. 18 shows a schematic drawing representing any of the engines ofFIG. 3-FIG. 11, depicting an alternative type of auxiliary compressor 2′and a system of providing a means for disabling or cutting out theauxiliary compressor when high charge pressure and density is notneeded. For relieving compressor 2′ of work, shutter valve 5 is closedand air bypass valve is opened so that air pumped through compressor 2′can re-circulate through compressor 2′ without requiring compressionwork.

FIG. 19 is a schematic drawing representing the engines shown in FIGS.5-7 and FIGS. 9-10 and having two compressors, and one intercooler forone stage of compression, dual intercoolers for a second stage ofcompression, dual manifolds, four valves and an engine control module(ECM) and illustrating means of controlling charge-air density, pressureand temperature by varying directions and amounts of air flow throughthe various electronic or vacuum operated valves and their conduits.

FIG. 20 is a schematic drawing showing optional electric motor drive ofthe air compressors of the engines of FIG. 1 through FIG. 11.

FIG. 21 is a schematic transverse sectional view of a pre-combustionchamber, a combustion chamber and associated fuel inlet ducts andvalving suggested for gaseous or liquid fuel operation for the enginesof this invention or for any other internal combustion engine.

FIG. 22 is a part sectional view through one cylinder of an engineshowing an alternate construction whereby there is supplied two firingstrokes each revolution of the shaft for a 2-stroke engine and onefiring stroke each revolution of the shaft for a 4-stroke engine, havinga beam which pivots on its lower extremity, a connecting rod which isjoined mid-point of the beam and is fitted to the crankshaft of theengine, and whereby a means is provided for varying the compressionratio of the engine at will.

FIG. 23 is a part sectional view through one cylinder of an engineshowing an alternate construction whereby there is supplied two firingstrokes each crankshaft revolution for a 2-stroke engine and one firingstroke each revolution of the shaft for a 4-stroke engine, and wherebythe beam connecting the connecting rod and the piston pivots at a pointbetween the piston and the piston connecting rod, which connecting rodis attached to the crankshaft of the engine, and an alternate preferredmeans of power take-off from the piston by a conventional piston rod,cross-head and connecting rod arrangement.

FIG. 24 is a part sectional view through one cylinder of an engineshowing a means of providing extra burn-time each firing stroke in a2-stroke or 4-stroke engine.

FIG. 25 is a perspective view of the cylinder block and head of a sixcylinder internal combustion engine operating in a 2-stroke cycle andrepresenting a yet another embodiment of the apparatus of the presentinvention from which still another method of operation of can beperformed and will be described. Among its other components, thisembodiment is seen as having scavenging ports in the bottom of thepiston sleeves and having a primary and an ancillary compressor, acooling system, valves and conduits to control the pressure, density andtemperature of the charge-air, and valves and conduits to supplyscavenging air to the cylinders.

FIG. 26 is a schematic drawing of an engine similar to the engine ofFIG. 25 showing one intercooler for one optional stage of compression,dual intercoolers for a primary compression stage and showing a controlsystem (including engine control module (ECM) and valving) forcontrolling charge-air density, weight, temperature and pressure bycontrolling directions and amounts of air flow through the variousvalves, conduits and an optional throttle valve, and showing twooptional routes for supplying scavenging air to the scavenging ports inthe bottom of the cylinders, and alternative routes for the exhaustedgases to exit the engine.

FIG. 27 through FIG. 30 are schematic drawings of the engine of FIG. 25and FIG. 26 showing four alternate methods suggested for efficientscavenging of the engines, FIG. 27 and FIG. 28 also show a schematicdrawing for an engine control module (ECM) and valving to controlcharge-air and scavenging air at a pressure density and temperaturedeemed appropriate for each.

FIG. 31 is a schematic drawing showing suggested optional electric motordrive for the engine's air compressors.

FIG. 32 is a schematic drawing of the 2-stroke engine of FIG. 25 andFIG. 26, having only one compressor for supplying both charge-air andscavenging air, and showing a control system and means of controllingcharge and scavenging air at a pressure, density and temperature deemedappropriate for each, and showing means of channeling the air throughdifferent paths for the same purpose;

FIG. 33 is a schematic transverse sectional view through a six cylinderengine having two compressor cylinders, four power cylinders, onesupercharger, five regulatory valves, and showing an engine controlmodule (ECM) for controlling charge temperatures, density and weight,and adopted for storage of compressed air compressed by regenerativebraking, or for storage of bleed-air produced in some industrialprocesses, in any of the engines of this invention.

FIG. 34 is a schematic drawing representing any of the engines of thepresent invention and showing an alternate embodiment which includes aseparate, electric-powered air compressor and, alternatively, anentrance conduit leading from a supply of waste or “bleed” compressedair for supplying charge-air to the engine (or to a plurality ofengines), whereby the need for engine-powered compressors is eliminated.

FIG. 35 is a schematic drawing representing any of the engines of thepresent invention depicted in an alternate embodiment which isconfigured to operate as a constant load and constant speed engine. Thisconstant load and constant speed engine embodiment of the presentinvention is shown as including both a primary and an ancillarycompressor with optional intercoolers for providing two stages ofpre-compressed charge-air, either optionally intercooled oradiabatically compressed.

FIG. 36 is a schematic drawing representing any of the engines of thepresent invention, and depicting a constant load and constant speedengine in accordance with an alternate embodiment of the presentinvention in which there is provided a single compressor with optionalintercoolers for providing a single stage of pre-compressed charge-air,either optionally intercooled or adiabatically compressed.

DETAILED DESCRIPTION OF THE DRAWINGS

With reference now in greater detail to the drawings, a plurality ofalternate, preferred embodiments of the apparatus of the ImprovedInternal Combustion Engine 100 of the present invention are depicted.Like components will be represented by like numerals throughout theseveral views; and, in some but not all circumstances, as the writermight deem necessary (due to the large number of embodiments), similarbut alternate components will be represented by superscripted numerals(e.g., 100 ¹). When there are a plurality of similar components, theplurality is often times referenced herein (e.g., six cylinders 7 a-7f), even though fewer than all components are visible in the drawing.Also, components which are common among multiple cylinders are sometimeswritten with reference solely to the common numeral, for ease ofdrafting—e.g. piston 22 a-22 f=>piston 22. In an effort to facilitatethe understanding of the plurality of embodiments, (but not to limit thedisclosure) some, but not all, sections of this Detailed Description aresub-titled to reference the system or sub-system detailed in the subjectsection.

The invented system of the present invention is, perhaps, best presentedby reference to the method(s) of managing combustion charge densities,temperatures, pressures and turbulence; and the following descriptionattempts to describe the preferred methods of the present invention byassociation with and in conjunction with apparatuses configured for andoperated in accordance with the alternate, preferred methods.

Some, but not necessarily all, of the system components that are commonto two or more of the herein depicted embodiments include a crankshaft20, to which are mounted connecting rods 19 a-19 f, to each of which ismounted a piston 22 a-22 f; each piston traveling within a powercylinder 7 a-7 f; air being introduced into the cylinders through inletports controlled by intake valves 16, and air being exhausted from thecylinders through exhaust ports controlled by exhaust valves 17. Theinteraction, modification and operation of these and such othercomponents as are deemed necessary to an understanding of the variousembodiments of the present invention are expressed below.

The Engine 100 ¹ of FIG. 1

Referring now to FIG. 1, there is shown a six cylinder reciprocatinginternal combustion engine 100 ¹ in which all of the cylinders 7 a-7 f(only one of which is shown in a sectional view) and associated pistons22 a-22 f operate in a 4-stroke cycle and all power cylinders are usedfor producing power to a common crankshaft 20 via connecting rods 19a-19 f, respectively. An ancillary compressor 2 (herein depicted as aLysholm rotary compressor) selectably supplies air which has beencompressed, or allows delivery of air therethrough at atmosphericpressure, to manifolds 13 and 14 and to cylinders 7 a-7 f, whichcylinders operate in a 4-stroke cycle. Valves 3, 5 and 6 andintercoolers 10, 11 and 12 are used, in the preferred embodiments, tocontrol air charge density, weight, temperature and pressure. The intakevalves 16 a-16 f, 16 a′-16 f′ are timed to control the compression ratioof the engine 100 ¹. The combustion chambers are sized to establish theexpansion ratio of the engine.

The engines 100 ¹-100 ⁵, 100 ⁷ of FIG. 1, FIG. 2, FIG. 3, FIG. 4, FIG.5, and FIG. 7, respectively, have camshafts 21 fitted with cams and arearranged to be driven at one-half the speed of the crankshaft in orderto supply one power stroke for every two revolutions of the crankshaft,for each power piston. The rotary compressors 2 of FIG. 1, FIG. 2, FIG.3, FIG. 4, FIG. 4-B, FIG. 5, FIG. 7 and FIG. 33 can be driven by aribbed V-belt and would have a step-up gear between the V pulley and thecompressor drive shaft, the rotary compressors could also be fitted witha variable-speed step-up gear as in some aircraft engines. Thereciprocating compressor 1 of FIG. 3 is shown as having double-actingcylinders linked to the crankshaft 20 by a connecting rod 19 g; and thecrankshaft 20 to which it is linked by connecting rod 19 g would supplytwo working strokes for each revolution of the crankshaft 20. In onealternate approach, the reciprocating compressor 1 is driven by theconnecting rod 19 g being connected to a short crankshaft above the maincrankshaft 20 to which the ancillary crankshaft (not shown) would begeared by a step-up gear in order to provide more than two workingstrokes per revolution of the main crankshaft 20. Alternatively, thecompressor system can have multiple stages of compression for eitherrotary or reciprocating compressors. Whereas, the ancillary compressor 1and second ancillary compressor 2 of the various embodiments aredepicted throughout as a reciprocating compressor or a rotarycompressor, it is noted that the invention is not limited by the type ofcompressor utilized for each; and the depicted compressors may beinterchanged, or may be the same, or may be other types of compressorsperforming the functions described herein.

The engine 100 ¹ shown in FIG. 1 is characterized by a more extensiveexpansion process, a low compression ratio and the capability ofproducing a combustion charge varying in weight from lighter-than-normalto heavier-than-normal, and capable of providing, selectively, a meaneffective cylinder pressure higher than can the conventional arrangementof normal engines but capable of having a lower maximum cylinderpressure in comparison to conventional engines An engine control module(ECM) (not shown in FIG. 1) and variable valves 3, 5 and 6 on conduits,as shown, provide a system for controlling the charge density, pressure,temperature, and the mean and peak pressure within the cylinder whichallows greater fuel economy, production of greater torque and power atlow RPM, with low polluting emissions for both spark andcompression-ignited engines. In alternate embodiments, a variable valvetiming system can be used and, with a control system such as an ECM, cancontrol the time of opening and the time of closing of the intake valves16 and 16′ to further provide an improved management of conditions inthe combustion chambers of cylinders 7 a-7 f of the engine 100 ¹ toallow for a flatter torque curve and higher power, when needed, and withlow levels of both fuel consumption and polluting emissions.

Brief Description of Operation of the Engine 100 ¹ Shown in FIG. 1

The engine 100 ¹ of this invention shown in FIG. 1 is a high efficiencyengine that attains both high power and torque with low fuel consumptionand low polluting emissions. The new working cycle is an externalcompression type combustion cycle. In this cycle, part of the intake air(all of which is compressed in the power cylinders in conventionalengines) is, selectively, compressed by at least one ancillarycompressor 2. The temperature rise during compression can be suppressedby use of air coolers 10, 11, 12 which cool the intake air, and by ashorter compression stroke.

One suggested, preferred method of operation of the new-cycle engine 100¹ is thus:

-   -   1. Depending upon the power requirements of the engine (e.g.,        differing load requirements), either intake air at atmospheric        pressure or intake air that has been compressed by at least one        ancillary compressor 2 and has had its temperature and pressure        controlled by bypass systems and charge-air coolers, is drawn        into the power cylinder 7 by the intake stroke of piston 22.    -   2. (a) After the intake stroke is complete, the intake valve 16        (which can be single or multiple, 16, 16′) is left open for a        period of time after the piston 22 has passed bottom dead        center, which pumps part of the fresh air charge back into the        intake manifold 13, 14. The intake valve 16, 16′ is then closed        at a point which action seals the cylinder 7, thus establishing        the compression ratio of the engine.    -   (b) Alternatively, the intake valve 16, 16′ is closed early,        during the intake stroke, before the piston 22 has reached        bottom dead center. The trapped air charge is then expanded to        the full volume of the cylinder 7 and compression of the charge        starts when the piston 22 returns to the point in the        compression stroke at which the intake valve 16, 16′ closed.    -   3. (a) During the compression stroke of piston 22, at the point        the intake valve 16 closed, either in 2(a) or 2(b) operation,        compression begins, producing a small compression ratio. This        makes it possible to restrain the temperature rise during the        compression stroke.    -   (b) During light-load operation, such as in vehicle cruising or        light-load power generation, the shutter valve 5 is closed and        the air bypass valve (ABV) 6 on the compressor is, preferably        opened so that the intake air is returned to the intake conduit        8 of the compressor 2 without being compressed. Shutter valve 3        can then direct the air charge around or through intercoolers 11        and 12. During this time, the engine pistons 22 a-22 f are        drawing in naturally aspirated air through the compressor 2.        This reduces compressor drive work and improves fuel economy.    -   (c) When more power is required, the charge density and pressure        can be increased by closing air bypass valve (ABV) 6 causing        compressor 2 to raise the air pressure and, alternatively, this        can be accomplished by either cutting in a second stage of        compression by compressor 1, as shown in FIG. 2, or by        increasing the speed of compressor 2. At the same time, control        valves 5 and 3 preferably, direct some or all of the air charge        through one or more of intercoolers 10, 11, and 12 in order to        increase charge-air density.    -   4. Compression continues, fuel is added, if not already present,        the charge is ignited and combustion produces a large expansion        of the gases against the piston 22 producing great energy in        either mode 3(a), (b) or (c). This energy produces a high mean        effective cylinder pressure and is converted into high torque        and power, especially in mode (c).        Detailed Description of Operation of the Engine 100 ¹ of FIG. 1

During the intake (1st) stroke of the piston 22 air flows through airconduits 15 from a manifold of air 13 or 14, which air (depending onpower requirements) is either at atmospheric pressure or has beencompressed to a higher pressure by compressor 2, through the intakevalve 16 into the cylinder 7. During the intake stroke of piston 22 theintake valve 16 closes early (at point x). From this point, the cylinder7 contents are expanded to the maximum volume of the cylinder. Then,during the compression (2nd) stroke, no compression takes place untilthe piston 22 has returned to the point x where the intake valve 16 wasclosed during the intake stroke. (At point x, the remaining displacedvolume of the cylinder is divided by the volume of the combustionchamber, to establish the compression ratio of the engine.)Alternatively, during the intake (1st) stroke of piston 22, the intakevalve 16 is held open through the intake stroke and past bottom deadcenter piston position, and through part of the compression (2nd) strokefor a significant distance, 10% or, to perhaps 50% or more of thecompression stroke, thus pumping some of the charge-air back into intakemanifold 13 or 14, and the intake valve 16 then closes to establish alow compression ratio in the cylinders of the engine. At the time ofclosure of intake valve 16, the density, temperature and pressure of thecylinder will be at approximate parity with the manifold 13 or 14contents.

During light-load operation, such as in vehicle cruising or light-loadpower generation, the shutter valves 5 and 3 are closed and the airbypass valve (ABV) 6 on the compressor is, preferably, opened so thatthe intake air is returned to the intake conduit 8 of the compressor 2without being compressed. During this time the engine pistons 22 a-22 fare drawing in naturally aspirated air through the compressor 2. Thisreduces compressor drive work and improves fuel economy.

When medium torque and power is needed, such as highway driving ormedium electric power generation, preferably the shutter valve 5 tocompressor 2 is closed and the air bypass valve (ABV) 6 is closed also.This causes the atmospheric pressure intake air to cease re-circulatingthrough the compressor 2 and the compressor 2 begins to compress thecharge-air to a higher-than-atmospheric pressure, while the closedshutter valves 5 and 3 direct the charge-air through conduits 104, 110,111, and 121/122 bypassing the air coolers 10, 11 and 12, with thecharge-air going directly to the manifolds 13 and 14 to power cylinders7 a-7 f where the denser, but hot, charge increases the mean effectivecylinder pressure of the engine to create greater torque.

When more power is needed, such as when rapid acceleration is needed orfor heavy-load electric power generation, preferably the air bypassvalve (ABV) 6 is closed and the shutter valves 3 or 5 or both areopened. This causes the compressor 2 to compress all of the air charge.Shutter valves 3 or 5 or both then supply (depending on the respectiveopened/closed conditions of valves 3 and 5), the conditioned air chargethrough conduits 105 or 104, to conduit 110, and then through conduits111 or 112 to the manifolds, 13, 14 and to the cylinders 7 a-7 f viaone, two, or all three of the charge coolers 10, 11 and 12. The verydense cooled air charge when mixed with fuel and ignited and expandedbeyond the compression ratio of the engine produces great torque andpower.

When greater power is needed the charge-air density and weight can beincreased by increasing the speed of the compressor 2 or by cutting in asecond compressor as in FIG. 2, for a second stage of pre-compression.The latter can be done by the engine control module 27 signaling airbypass valve (ABV) 6, FIG. 2. to close to prevent re-circulation of partof the intake air into conduit 103 which negates, selectively, anysecond compression stage during light-load operation. At the time airdensity and pressure is increased, shutter valves 3 and 5 can directpart of all of the air charge through intercoolers 10, 11 and 12 inorder to condense the charge and lessen the increase in the chargetemperature and pressure, both accomplished by the cooling of thecharge. This increases the mean effective cylinder pressure duringcombustion for high torque and power.

The heavier the weight of the air charge and the denser the charge, theearlier in the intake stroke (or the later in the compression stroke)the intake valve can be closed to establish a low compression ratio andretain power, and the less heat and pressure is developed duringcompression in the cylinder. In this 4-stroke engine the intake chargecan be boosted in pressure by as much as 4-5 atmospheres and if thecompression ratio is low enough, say 4:1 to 8:1 (higher for dieselfuel), even spark-ignited there would be no problem with detonation. Theexpansion ratio should still be large, 14:1 would be a preferredexpansion ratio for spark ignition, perhaps 19:1 for diesel operation.

The compression ratio is established by the displaced volume of thecylinder 7 remaining after point x has been reached in the compressionstroke (and intake valve 16 is closed) being divided by the volume ofthe combustion chamber. The expansion ratio in all cases is greater thanthe compression ratio. The expansion ratio is established by dividingthe total displaced volume of the cylinder by the volume of thecombustion chamber.

Fuel can be carbureted, or it can be injected in a throttle-body 56(seen in FIG. 16), or the fuel can be injected into the inlet stream ofair, injected into a pre-combustion chamber (FIG. 21) or, injectedthrough the intake valve 16, or it may be injected directly into thecombustion chamber. If injected, it should be at or after the piston 22has reached point x and the intake valve is closed. The fuel can also beinjected later, similar to diesel operation, and can be injected at theusual point for diesel oil injection, perhaps into a pre-combustionchamber or directly into the combustion chamber or directly onto a glowplug. Some fuel can be injected after top dead center even continuouslyduring the first part of the expansion stroke for a mostly constantpressure combustion process.

Ignition can be by compression (which may be assisted by a glow plug),or by electric spark. Spark ignition can take place before top deadcenter, as normally done, at top dead center or after top dead center.

At an opportune time the air-fuel charge is ignited and the gases expandagainst the piston for the power (3rd) stroke. Near bottom dead centerat the opportune time exhaust valve(s) 17 open and piston 22 rises inthe scavenging (4th) stroke, efficiently scavenging the cylinder bypositive displacement, after which exhaust valve(s) 17 closes.

This completes one cycle of the 4-stroke engine.

The Engine 100 ² of FIG. 2

Referring now to FIG. 2, there is shown a six cylinder reciprocatinginternal combustion engine 100 ² in which all of the cylinders 7 a-7 f(only two 7 a, 7 f of which are shown in a schematic drawing) andassociated pistons 22 a-22 f operate in a 4-stroke cycle and all powercylinders are used for producing power to a common crankshaft 20 viaconnecting rods 19 a-19 f, respectively. An ancillary compressor 2(herein depicted as a rotary compressor) supplies air which has beencompressed, or allows delivery of air therethrough at atmosphericpressure, to manifolds 13 and 14 and to cylinders 7 a-7 f whichcylinders operate in a 4-stroke cycle. A second ancillary compressor 1is used, selectively, to boost the air pressure to compressor 2. Valves3, 4, 5 and 6 and intercoolers 10, 11 and 12 are used, in the preferredembodiments, to control air charge density, weight, temperature andpressure. The intake valves 16 a-16 f are timed to control thecompression ratio of the engine 100 ². The combustion chambers are sizedto establish the expansion ratio of the engine.

The engine 1002 shown in FIG. 2 is characterized by a more extensiveexpansion process, a low compression ratio and the capability ofproducing a combustion charge varying in weight from lighter-than-normalto heavier-than-normal, and capable of selectively providing a meaneffective cylinder pressure higher than can the conventional arrangementof normal engines but having similar or lower maximum cylinder pressurein comparison to conventional engines. An engine control module (ECM) 27and variable valves 3, 4, 5 and 6 on conduits, as shown, provide asystem for controlling the charge density, pressure, temperature, andthe mean and peak pressure within the cylinder which allows greater fueleconomy, production of greater torque and power at low RPM, with lowpolluting emissions for both spark and compression-ignited engines. Inalternate embodiments, a variable valve timing system can be used and,with a control system such as an engine control module (ECM) 27, cancontrol the time of opening, and the time of closing of the intakevalves 16 to further provide an improved management of conditions in thecombustion chambers of cylinders 7 a-7 f of the engine 100 ² to allowfor a flatter torque curve and higher power, and with low levels of bothfuel consumption and polluting emissions.

Brief Description of Operation of the Engine 100 ² of FIG. 2

The engine 100 ² of this invention shown in FIG. 2 is a high efficiencyengine that attains both high power and torque with low fuel consumptionand low polluting emissions. The new working cycle is an externalcompression type combustion cycle. In this cycle, part of the intake air(all of which is compressed in the power cylinders in conventionalengines) is compressed, selectively, by at least one ancillarycompressor 1, 2. The temperature rise during compression can besuppressed by use of air coolers 10, 11, 12, which cool the intake air,and by a shorter compression stroke.

One suggested, preferred method of operation of the new-cycle engine 100² is thus:

-   -   1. Depending upon the power requirements of the engine (e.g.,        differing load requirements), either intake air at atmospheric        pressure or intake air that has been compressed by at least one        ancillary compressor and has had its temperature and pressure        adjusted by bypass systems and charge-air coolers, is drawn into        the power cylinder 7 by the intake stroke of piston 22.    -   2. (a) After the intake stroke is complete, the intake valve 16        (which can be single or multiple) is left open for a period of        time after the piston 22 has passed bottom dead center which        pumps part of the fresh air charge back into the intake manifold        13, 14. The intake valve 16 is then closed at a point which        action seals cylinder 7, thus establising the compression ratio        of the engine.    -   (b) Alternatively, the intake valve 16 is closed early, during        the intake stroke, before the piston 22 has reached bottom dead        center. The trapped air charge is then expanded to the full        volume of the cylinder 7 and compression of the charge starts        when the piston 22 reaches the point in the compression stroke        at which the intake valve 16 closed.    -   3. (a) During the compression stroke of piston 22, at the point        the intake valve 16 closed, either in 2(a) or 2(b) operation,        compression begins, producing a small compression ratio. This        makes it possible to lessen the temperature rise during the        compression stroke.    -   (b) During light-load operation, such as in vehicle cruising or        light-load power generation, the shutter valves 3 and 5 are        closed and the air bypass valves (ABV) 4 and 6 to both        compressors 1 and 2 are, preferably, opened so that the intake        air is returned to the intake conduits 110 and 103 of the        compressors 2 and 1 without being compressed. During this time,        the engine pistons 22 a-22 f are drawing in naturally aspirated        air past the compressor(s). This reduces compressor drive work        and further improves fuel economy.    -   (c) When greater power is required, the charge density and        pressure can be increased by closing air bypass valve (ABV) 4        causing compressor 2 to raise the charge-air pressure and, in        addition, by either cutting in the second stage of compression        by compressor 1 in the same manner, that of closing air bypass        valve ABV 6, or by increasing the speed of compressor 2 or of        both compressors. At the same time, shutter valves 3 and 5 would        be opened to direct some or all of the air charge through        intercoolers 10, 11 and 12 in order to increase charge-air        density.    -   4. Compression continues, fuel is added if not already present,        the charge is ignited and combustion produces a large expansion        of the gases against piston 22 producing great energy in either        mode 3(a), (b) or (c). This energy produces a high mean        effective cylinder pressure and is converted into high torque        and power, especially in mode (c).        Detailed Description of Operation of the Engine 100 ² of FIG. 2

During the intake (1st) stroke of the piston 22 air flows through airconduits 15 from the manifold 13 or 14 of air which air (depending onpower requirements) is either at atmospheric pressure or has beencompressed to a higher pressure by compressor 2 and/or compressor 1,through the intake valve 16 into the cylinder 7. During the intakestroke of piston 22 the intake valve 16 closes at point x sealingcylinder 7. From this point the air charge is expanded to the maximumvolume of the cylinder. Then during the compression (2nd) stroke, nocompression takes place until the piston 22 has returned to the point xwhere the intake valve 16 was closed during the intake stroke. (At pointx, the remaining displaced volume of the cylinder is divided by thevolume of the combustion chamber, to establish the compression ratio ofthe engine.) Alternatively, during the intake (1st) stroke of piston 22,the intake valve 16 is held open through the intake stroke and passedbottom dead center, and through part of the compression (2nd) stroke fora significant distance, 10% or, to perhaps 50% or more of thecompression stroke, thus pumping some of the charge-air back into intakemanifold 13 or 14, and the intake valve 16 then closes, sealing cylinder7, to establish a low compression ratio in the cylinders of the engine.At the time of closure of intake valve 16, the density, temperature andpressure of the cylinder 7 contents will be approximately the same asthat of the air charge in the intake manifolds 13 and 14.

During light-load operation, such as in vehicle cruising or light-loadpower generation, the shutter valves 3 and 5 are closed and the airbypass valves (ABV) 4 and 6 to both compressors 1 and 2 are, preferablyopened so that the intake air is returned to the intake conduits 110 and103 of the compressors 2 and 1 without being compressed. During thistime the engine pistons 22 a-22 f are drawing in naturally aspirated airpast the compressor(s). This reduces compressor drive work and furtherimproves fuel economy.

When medium torque and power is needed, such as highway driving ormedium electric power generation, preferably the shutter valves 3 and 5are closed and the air bypass valves (ABV) 4 and 6 are closed. Thiscauses the atmospheric pressure intake air to cease re-circulatingthrough the compressor 2 and 1 and both compressors begin to compressthe charge-air to a higher-than-atmospheric pressure, while the closedshutter valves 3 and 5 direct the charge-air through conduits 104, 110,111, and 121/122 bypassing the air coolers 10, 11 and 12, in FIG. 2,with the charge-air going directly to the manifold 13 and 14 and topower cylinders 7 a-7 f where the denser, but hot, charge increases themean effective cylinder pressure of the engine to create greater torqueand power.

When more power is needed, such as when rapid acceleration is needed orfor heavy-load electric power generation, preferably the air bypassvalve (ABV) 4 is closed and the shutter valve 3 is opened. This causesthe compressor 2 to compress all of the air charge and shutter valve 3directs the air charge through conduits 112 and 113 and the compressedcharge-air is supplied to the manifolds 13 and 14 and to the cylinders 7a-7 f via the charge coolers 11 and 12. For even greater power theshutter valve 5 is opened and the air bypass valve 6 is closed andcompressor 1 begins a second stage of compression, and all of the aircharge is now directed through intercoolers 10, 11 and 12 for highcharge density. The very dense cooled air charge when mixed with fueland ignited and expanded beyond the compression ratio of the engineproduces great torque and power.

The heavier the weight of the air charge and the denser the charge, theearlier (or later) the intake valve can be closed to establish a lowcompression ratio and retain power, and the less heat and pressure isdeveloped during compression in the cylinder. In this 4-stroke enginethe intake charge can be boosted in pressure by as much as 4-5atmospheres and if the engine's compression ratio is low enough, say 4:1to 8:1 (higher for diesel fuel), even spark-ignited there would be noproblem with detonation. The expansion ratio would still be very large,14:1 would be a preferable expansion ratio for spark ignition, perhaps19:1 for diesel operation.

The compression ratio is established by the displaced volume of thecylinder 7 remaining after point x has been reached in the compressionstroke (and intake valve 16 is closed) being divided by the volume ofthe combustion chamber. The expansion ratio in all cases is greater thanthe compression ratio. The expansion ratio is established by dividingthe total displaced volume of the cylinder by the volume of thecombustion chamber.

Fuel can be carbureted, or it can be injected in a throttle-body 56(seen in FIG. 16), or the fuel can be injected into the inlet stream ofair, injected into a pre-combustion chamber as in FIG. 21 or, injectedthrough the intake valve 16, or it may be injected directly into thecombustion chamber. If injected, it should be at or after the piston 22has reached point x and the intake valve is closed. The fuel can also beinjected later and in the case of diesel operation can be injected atthe usual point for diesel oil injection, perhaps into a pre-combustionchamber or directly into the combustion chamber or directly onto a glowplug.

At an opportune time the air-fuel charge is ignited and the gases expandagainst the piston for the power (3rd) stroke. Near bottom dead centerat the opportune time exhaust valve(s) 17 open and piston 22 rises inthe scavenging (4th) stroke, efficiently scavenging the cylinder bypositive displacement, after which the exhaust valve(s) closes.

This completes one cycle of the 4-stroke engine.

The Engine 100 ³ of FIG. 3

Referring now to FIG. 3, there is shown a six cylinder reciprocatinginternal combustion engine 1003 in which all of the cylinders 7 a-7 f(only one of which is shown in a sectional view) and associated pistons22 a-22 f operate in a 4-stroke cycle and all power cylinders are usedfor producing power to a common crankshaft 20 via connecting rods 19a-19 f, respectively. An ancillary reciprocating compressor 1 and anancillary rotary compressor 2 supply pressurized charge air which hasbeen compressed, or allow deliver of air therethrough at atmosphericpressure, to manifolds 13, 14 and to cylinders 7 a-7 f, which cylindersoperate in a 4-stroke cycle. Valves 3, 4, 5 and 6 and intercoolers 10,11 and 12 are used, in the preferred embodiments, to control air chargedensity, weight, temperature and pressure. The intake valves 16 aretimed to control the compression ratio of the engine 100 ³. Thecombustion chambers are sized to establish the expansion ratio of theengine.

The engine 100 ³ shown in FIG. 3 is characterized by a more extensiveexpansion process, a low compression ratio and the capability ofproducing a combustion charge varying in weight from lighter-than-normalto heavier-than-normal, and capable of selectively providing a meaneffective cylinder pressure higher than can the conventional arrangementof normal engines but having similar or lower maximum cylinder pressurein comparison to conventional engines. An engine control module (ECM) 27and variable valves 3, 4, 5 and 6 on conduits, as shown, provide asystem for controlling the charge density, pressure, temperature, andthe mean and peak pressure within the power cylinder 7 which allowsgreater fuel economy, torque and power at low RPM, with low pollutingemissions for both spark and compression-ignited engines. In alternateembodiments, a variable valve timing system can be used and, with acontrol system such as an engine control module (ECM) 27, can controlthe time of opening and the time of closing of the intake valves 16 tofurther provide an improved management of conditions in the combustionchambers of cylinders 7 a-7 f of the engine 100 ³ to allow for a flattertorque curve and high power and with low levels of both fuel consumptionand polluting emissions.

Brief Description of Operation of the Engine 100 ³ of FIG. 3

The engine 100 ³ of this invention shown in FIG. 3 is a high efficiencyengine that attains both high power and torque with low fuel consumptionand low polluting emissions. The new working cycle is an externalcompression type combustion cycle. In this cycle part of the intake air(all of which is compressed in the power cylinders in conventionalengines) is selectively compressed by at least one ancillary compressor1, 2. The temperature rise during compression can be suppressed by useof air coolers 10, 11, 12, which cool the intake air, and by a shortercompression stroke.

One suggested, preferred method of operation of the new-cycle engine 100³ is thus:

-   -   1. Depending upon the power requirements of the engine (e.g.,        differing load requirements), either intake air at atmospheric        pressure or intake air that has been compressed by at least one        ancillary compressor and has had its temperature and pressure        adjusted by bypass systems and charge-air coolers, is drawn into        the power cylinder 7 by the intake stroke of piston 22.    -   2. (a) After the intake stroke is complete the intake valve 16        (which can be single or multiple, 16, 16′) is left open for a        period of time after the piston 22 has passed bottom dead center        which pumps part of the fresh air charge back into the intake        manifolds 13, 14. The intake valve 16 is then closed at a point        which seals cylinder 7, thus establishing the compression ratio        of the engine.    -   (b) Alternatively, the intake valve 16 is closed early, during        the intake stroke, before the piston 22 has reached bottom dead        center. The trapped air charge is then expanded to the full        volume of the cylinder 7 and compression of the charge starts        when the piston 22 reaches the point in the compression stroke        at which the intake valve 16 closed.    -   3. (a) During the compression stroke of piston 22, at the point        the intake valve 16 closed, either in 2(a) or 2(b) operation,        compression begins, producing a small compression ratio. This        makes it possible to lessen the temperature rise during the        compression stroke.    -   (b) During light-load operation, such as in vehicle cruising or        light-load power generation, the shutter valves 3 and 5 are        closed and the air bypass valves (ABV) 4 and 6 on both        compressors 1 and 2 are, preferably, opened so that the intake        air is returned to the intake conduits 110 and 8 of the        compressors 1 and 2 without being compressed. During this time        the engine pistons 22 a-22 f are drawing in naturally aspirated        air past the compressor(s). This reduces compressor drive work        and further improves fuel economy.    -   (c) When greater power is required, the charge density and        pressure can be increased by closing air bypass valve (ABV) 4        causing compressor 1 to raise the charge-air pressure and, in        addition, by either cutting in the second stage of compression        by compressor 2, if needed, in the same manner, that of closing        ABV valve 6, or by increasing the speed of compressors 1 or 2,        or both. At the same time, shutter valves 3 and 5 would direct        some or all of the air charge through intercoolers 10, 11, and        12 in order to increase charge-air density.    -   4. Compression continues, fuel is added if not already present,        the charge is ignited and combustion produces a large expansion        of the gases against piston 22 producing great energy in either        mode 3(a), (b) or (c). This energy produces a high mean        effective cylinder pressure and is converted into high torque        and power, especially in mode (c).        Detailed Description of Operation of the Engine 100 ³ of FIG. 3

During the intake (1st) stroke of the piston 22 air flows through airconduits 15 from the manifold 13 or 14 of air which air (depending onpower requirements) is either at atmospheric pressure or has beencompressed to a higher pressure by compressor 1 or 2 through the intakevalve 16 into the cylinder 7. During the intake stroke of piston 22 theintake valve 16 closes (at point x). From this point the cylindercontents are expanded to the maximum volume of the cylinder. Then duringthe compression (2nd) stroke, no compression takes place until thepiston 22 has returned to the point x where the intake valve 16 wasclosed, sealing the cylinder 7, during the intake stroke. (At point x,the remaining displaced volume of the cylinder is divided by the volumeof the combustion chamber, to establish the compression ratio of theengine.) Alternatively, during the intake (1st) stroke of piston 22, theintake valve 16 can be held open through the intake stroke passed bottomdead center, and through part of the compression (2nd) stroke for asignificant distance. 10% to perhaps 50% or more of the compressionstroke pumping some of the charge-air back into intake manifold, and theintake valve 16, 16′ then closes to establish a low compression ratio inthe cylinders of the engine.

During light-load operation, such as in vehicle cruising or light-loadpower generation, the shutter valves 3 and 5 are closed and the airbypass valves (ABV) 4 and 6 on both compressors 1 and 2 are, preferably,opened so that the intake air is returned to the intake conduits 110 and8 of the compressors 1 and 2 without being compressed. During this timethe engine pistons 22 a-22 f are drawing in naturally aspirated air pastthe compressor(s). This reduces compressor drive work and furtherimproves fuel economy.

When medium torque and power is needed, such as highway driving ormedium electric power generation, preferably the shutter valve 3 tocompressor 1 is opened, the air bypass valve (ABV) 4 is closed and ABV 6remains open. This causes the atmospheric pressure intake air to ceasere-circulating through the compressor 1; and the compressor 1, alone,begins to compress the charge-air to a higher-than-atmospheric pressure,while the closed shutter valves 3 and 5 directs the charge-air throughconduits 104, 110, 111, and 121/122 bypassing the air coolers 10, 11 and12, in FIG. 3, with the charge-air going directly to the manifolds 13and 14 and to power cylinders 7 a-7 f where the denser heated chargeincreases the mean effective cylinder pressure of the engine to creategreater torque and power.

When more power is needed, such as when rapid acceleration is needed orfor heavy-load electric power generation, preferably the air bypassvalves (ABV) 4 and 6 are closed and the shutter valves 3 and 5 areopened on both compressors. This causes the compressors 1 and 2 tocompress all of the air charge and shutter valves 3 and 5 direct the aircharge away from conduit 8 and through the compressors 1 and 2, and thecompressed charge-air is then supplied through conduits 105, 106, 110,112, 113, 114 and 115 to the manifolds 13 and 14 and to the cylinders 7a-7 f via the charge coolers 10, 11 and 12. The very dense cooled aircharge when mixed with fuel and ignited and expanded beyond thecompression ratio of the engine produces great torque and power.

The heavier the weight of the air charge and the denser the charge, theearlier in the intake stroke (or the later in the compression stroke)the intake valve can be closed to establish a low compression ratio andretain power, and the less heat and pressure is developed duringcompression in the cylinder. In this 4-stroke engine the intake chargecan be boosted in pressure by as much as 4-5 atmospheres and if thecompression ratio is low enough, say 4:1 to 8:1 (higher for dieselfuel), even spark-ignited there would be no problem with detonation. Theexpansion ratio would still be very large, 14:1 would be a preferredexpansion ratio for spark ignition, perhaps 19:1 for diesel operation.

The compression ratio is established by the displaced volume of thecylinder 7 remaining after point x has been reached in the compressionstroke (and intake valve 16 is closed) being divided by the volume ofthe combustion chamber. The expansion in all cases is greater than thecompression ratio. The expansion ratio is established by dividing thetotal displaced volume of the cylinder by the volume of the combustionchamber.

Fuel can be carbureted, or it can be injected in a throttle-body, or thefuel can be injected into the inlet stream of air, injected into apre-combustion chamber, FIG. 21, or, injected through the intake valve16, or it may be injected directly into the combustion chamber. Ifinjected, it should be at or after the piston 22 has reached point x andthe intake valve is closed. The fuel can also be injected later and inthe case of diesel operation can be injected at the usual point fordiesel oil injection, perhaps into a pre-combustion chamber or directlyinto the combustion chamber or directly onto a glow plug.

At an opportune time the air-fuel charge is ignited and the gases expandthe piston 22 for the power (3rd) stroke. Near bottom dead center at theopportune time exhaust valve(s) 17 open and piston 22 rises in thescavenging (4th) stroke, efficiently scavenging the cylinder by positivedisplacement, after which exhaust valve(s) 17 closes.

This completes one cycle of the 4-stroke engine.

The Engine 100 ⁴ of FIG. 4

Referring now to FIG. 4, there is shown a six cylinder reciprocatinginternal combustion engine 100 ⁴ having two atmospheric air intakes 8and 9 and corresponding intake conduits 15-A, 15-B, in which all of thecylinders (only one (7) of which is shown in a sectional view) 7 a-7 fand associated pistons 22 a-22 f operate in a 4-stroke cycle and allpower cylinders are used for producing power to a common crankshaft 20via connecting rods 19 a-19 f, respectively. A compressor 2, in thisfigure a Lysholm type rotary compressor, is shown which, with airconduits as shown, supplies pressurized air to one or more cylinderintake valves 16-A. An air inlet 8 and an ancillary air inlet 9 andinlet conduits 15-A, 15-B selectably supply air charge at atmosphericpressure or air which has been compressed to a higher pressure toseparate intake valves 16-A and 16-B opening to the same cylinder 7 a-7f (for example, shown here opening to cylinder 7 f). Intercoolers 10, 11and 12 and control valves 3, 5 and 6 are used, in the preferredembodiments, to control the air charge density, weight, temperature andpressure. The intake valves 16 a-B-16 f-B which receive air throughmanifold 14-B and intake conduits 15 a-B to 15 f-B, are timed to controlthe compression ratio of the engine 100 ⁴. The combustion chambers aresized to establish the expansion ratio of the engine. Because ofnoticeable similarities between the engine 100 ⁴ of FIG. 4 and that ofFIG. 7 (where the auxiliary air inlet 9 system has been shown inphantom, for informational value), reference will be made as deemedhelpful to FIG. 7 for certain common components.

The engine 100 ⁴ shown in FIG. 4 is characterized by a more extensiveexpansion process, a low compression ratio and capable of producing acombustion charge varying in weight from lighter-than-normal toheavier-than-normal and capable of selectively providing a meaneffective cylinder pressure higher than can the conventional arrangementin normal engines with similar or lower maximum cylinder pressure incomparison to conventional engines. Engine control module (ECM) 27(refer, for example to FIG. 7) and variable valves 3, 5, and 6 onconduits, as shown, provide a system for controlling the chargepressure, density, temperature, and mean and peak pressure within thecylinder which allows greater fuel economy, production of greater powerand torque at all RPM, with low polluting emissions for both spark andcompression ignited engines. In alternate embodiments, a variable valvetiming system with the ECM 27 can also control the time of opening andclosing of the intake valves 16-A and/or 16-B, to further provide animproved management of conditions in the combustion chambers to allowfor a flatter torque curve, and higher power, with low levels of bothfuel consumption and polluting emissions.

Brief Description of Operation of the Engine 100 ⁴ Shown in FIG. 4

The new cycle engine 100 ⁴ of FIG. 4 is a high efficiency engine thatattains both high power and torque, with low fuel consumption and lowpolluting emissions. The new cycle is an external compression typecombustion cycle. In this cycle, part of the intake air (all of which iscompressed in the power cylinders in conventional engines) isselectively compressed by an ancillary compressor 2. The temperaturerise at the end of compression can be suppressed by use of air coolers10, 11, 12, which cool the intake air, by the late injection oftemperature-adjusted air, and by a shorter compression stroke.

During operation, a primary air charge is supplied to the cylinder 7through intake valve 16-B at atmospheric pressure or air which has beenincreased by perhaps one-half to one atmosphere through an ancillary airinlet 9 which can be carbureted. This charge can be compressed, fueladded if not present, ignited at the appropriate point near top deadcenter for the power stroke—providing high fuel economy and lowpolluting emissions.

When more power is desired, a secondary air charge originating from airinlet 8 is, preferably, introduced into the power cylinder 7 during thecompression stroke by a second intake valve 16-A which introduces ahigher pressure air charge after the first intake valve 16-B has closedin order to increase the charge density when needed. After the secondaryair charge has been injected, intake valve 16-A quickly closes. Theprimary air charge may be boosted to a higher pressure by cutting in asecond ancillary compressor, in series with compressor 2, (see forexample, compressor 1 in FIG. 7, where the primary compressor to be usedin the engine of FIG. 4 is the compressor 2—shown in FIG. 4 and FIG. 7,for example, as a Lysholm rotary type) between air inlet 8 and manifold13, 14, and can be intercooled. The temperature, pressure, amount andpoint of injection of the secondary charge, if added, is adjusted toproduce the desired results. An intake valve disabler (there are severalon the market, for example, Eaton Corp. and Cadillac), in preferredembodiments, may be used to disable intake valve 16—A when light-loadoperation does not require a high mean effective cylinder pressure.Alternatively, the air bypass valve (ABV) 6 is opened to re-circulatethe charge-air back through the compressor 2 in order to relieve thecompressor of compression work during light-load operation.

Alternatively, a one-way valve, one type of which is shown as 26 in FIG.6 can be utilized to provide a constant or a variable “pressure ratio”in the cylinder 7, while improving swirl turbulence. In this alternatemethod of operation the intake valve 16-A would close very late andvalve 26 would close only when the pressure in the cylinder 7 nearlyequates or exceeds the pressure in conduit 15-A. Thus, the pressure inconduit 15-A, controlled by compressor speed, along with valves 3, 5 and6 (and valve 4 in FIG. 7) would regulate the pressure, density,temperature and turbulence of the combustion process. A spring-retracteddisc type, metal or ceramic, or any other type of automatic valve couldreplace valve 26.

Another alternate method of providing a low compression ratio, with alarge expansion ratio and reduced polluting emissions is thus:

The air pressure supplied to intake runner-conduit 15-A is produced atan extremely high level, and intake valve 16-A is, in alternateembodiments, replaced by a fast-acting, more controllable valve such asbut not limited to a high speed solenoid valve (not shown), which valveis, preferably, either mechanically, electrically or vacuum operatedunder the control of an engine control module (ECM). In such anembodiment, a smaller, denser, temperature-adjusted, high-pressurecharge, with or without accompanying fuel, can, selectively, beinjected, tangentially oriented, much later in the compression stroke,or even during the combustion process, in order to increase chargedensity, to reduce peak and overall combustion temperatures, and tocreate the desired charge swirl turbulence in the combustion chamber(s).

One suggested, preferred method of operation of the new-cycle engine 100⁴ is thus:

-   -   1. Depending upon the power requirements of the engine (e.g.,        differing load requirements), either intake air at atmospheric        pressure or intake air that has been compressed by one        compressor (not shown) and has had its temperature adjusted by        bypass systems and charge-air coolers (not shown) is drawn into        the cylinder 7 (intake stroke) through air inlet 9, manifold        14-B, intake conduits 15-B, and intake valves 16 a-B-16 f-B by        intake stroke of piston 22.    -   2. (a) After the intake stroke is complete the intake valve 16-B        (which can be single or multiple), is left open for a period of        time after the piston 22 has passed bottom dead center, which        pumps part of the fresh air charge back into the intake manifold        14-B.    -   (b) Alternatively, the intake valve 16-B is closed early, during        the intake stroke before the piston reaches bottom dead center.        The trapped air charge is then expanded to the full volume of        the cylinder 7.    -   3. (a) The compression (2nd) stroke now begins and, at the point        the intake valve 16-B is closed to seal cylinder 7 in either        2(a) or 2(b) operation, compression begins (for a small        compression ratio). This makes it possible to lessen the        temperature rise during the compression stroke.    -   (b) When greater power is required a secondary compressed,        temperature-adjusted air charge is injected into the cylinder 7        by intake valve 16-A which opens and closes quickly during the        compression stroke at the point at which the intake valve 16-B        which introduced the primary air charge closes, or later in the        stroke, to produce a more dense, temperature controlled charge        in order to provide the torque and power desired of the engine.    -   (c) Alternatively, when greater power is required, the secondary        air charge can be increased in density and weight by causing        shutter valves 5 and 3 to direct all or part of the air charge        through one or more of intercoolers 10, 11 and 12 to increase        the charge density and/or by increasing compressor speed or by        cutting in a second stage of auxiliary compression, the latter        two actions thereby pumping in more air on the backside.        Alternatively, the timing of the closing of intake valve 16-B on        either the inlet or compression stroke can be altered        temporarily to retain a larger charge, and at the same time the        timing of intake valve 16-A can be temporarily altered to open        and close earlier during the compression stroke to provide a        larger dense, temperature-adjusted air charge.    -   4. Compression continues, fuel is added if not present, the        charge is ignited and combustion produces a large expansion of        the combusted gases against the piston 22 producing great energy        in either mode 3(a), (b), or (c). This energy is absorbed and        turned into high torque and power, especially in mode (c).    -   5. Near bottom dead center of the piston, exhaust valves 17 a-17        f, 17 a′-17 f′ open and the cylinder 7 is efficiently scavenged        by the (4th) stroke of piston 22, after which valve(s) 17 close.        Detailed Description of the Operation of the Engine 100 ⁴ of        FIG. 4

During the intake (1st) stroke of the piston 22 low pressure air flowsthrough air conduit 15-B from the atmospheric air inlet 9 throughmanifold 14-B of air at atmospheric pressure or which has been boostedin pressure (or, alternatively, the low pressure air can be supplied bya pressure regulator valve 25 and conduit 15-B from compressed air line15-A as shown in FIG. 5), through an intake valve 16-B into the cylinder7. During the intake stroke of piston 22, the intake valve 16-B closes(point x). From this point the air charge in the cylinder is expanded tothe maximum volume of the cylinder. Then, during the compression (2nd)stroke, no compression of the charge takes place until the piston 22returns to point x where the inlet valve was closed. (At point x, theremaining displaced volume of the cylinder is divided by the volume ofthe combustion chamber, establishing the compression ratio of theengine.) At any point in the compression stroke of piston 22 at the timeor after the piston 22 reaches point x a second inlet valve 16-A is,selectively, opened in order to inject a secondary pressurized aircharge at a temperature, density and pressure deemed advantageous to theengine load, torque demand, fuel economy and emissions characteristicsdesired. Alternatively, during the intake of charge-air by intake valve16-B, the intake valve 16-B is held open past bottom dead center for asignificant distance, 10% to perhaps 50% or more of the compressionstroke, thus pumping some of the charge back into the intake manifold14-B, and then closed to establish a low compression ratio in thecylinder. During the compression stroke, at or after the time intakevalve 16-B is closed, a secondary charge of high pressure,temperature-adjusted air which has been compressed by compressor 2 is,selectively, injected by a second intake valve 16-A, which opens andcloses quickly, into the same cylinder 7. Alternatively, when greatertorque and power are needed, the density of the secondary charge-air isgreatly increased by increasing the speed of the primary compressor 2 orby cutting in another stage of compression, as in item 1, FIG. 7, and/orby routing the air charge through intercoolers.

For light-load operation a shut-off valve, or a valve disabler 31 (suchas shown in FIG. 7) on the high pressure intake valve 16-A, preferably,temporarily restrains the intake air, or holds the valve closed. Thiswould add to the fuel economy of the engine. Alternatively, duringlight-load operation the shutter valve 5 is closed and the air bypassvalve ABV 6 is opened so that part or all of the air pumped bycompressor 2 would be returned to the inlet conduit of the compressor 2for a low, or no pressure boost. Therefore, when secondary intake valve16-A opens, the pressure of the air in conduit 15-A is approximately thesame as, or not much greater than that from the initial charge. In analternate embodiment, an ancillary automatic valve 26, FIG. 6, isarranged, as shown in FIG. 6, to prevent any back-flow of charge-airinto conduit 15-A if the cylinder pressure should exceed the pressure inconduit 15-A before intake valve 16-A closed during the compressionstroke of piston 22.

If an ancillary one-way valve (see valve 26 of FIG. 6) is present, thepressure ratio in cylinder 7 can be filly controlled by adjusting thepressure of the charge air passing through intake valve 16-A. Thepressure ratio can then be 20 controlled by valves 3, 5, 6 and bycompressor speed and any throttle valve that may be present. In the useof valve 26, intake valve 16-A must be kept open until very late in thecompression stroke, perhaps until piston 22 nears or reaches top deadcenter.

Fuel can be carbureted in FIG. 4, FIG. 4-B, FIG. 5, FIG. 7 and FIG. 33,injected in a throttle body 56 (seen in FIG. 16), or the fuel can beinjected into the inlet stream of air, injected into a pre-combustionchamber or, injected through intake valves 16-A, 16-B, (16-B only if16-B does not remain open past bottom dead center), or it may beinjected directly into the combustion chamber at point x during theintake stroke, (during the intake stroke only if intake valve 16-Bcloses before bottom dead center), or at the time or after the piston 22has reached point x in the compression stroke. The fuel can be injectedwith or without accompanying air. In the case of diesel operation, fuelcan be injected at the usual point for diesel oil injection, perhapsinto a pre-combustion chamber or directly into the combustion chamber ordirectly onto a glow plug.

After the temperature-and-density-adjusting-air charge has beeninjected, if used, compression of the charge continues and with fuelpresent, is ignited at the opportune time for the expansion (3rd andpower) stroke. (The compression ratio is established by the displacedvolume of the cylinder remaining after point x has been reached on thecompression stroke, being divided by the volume of the combustionchamber. The expansion ratio is determined by dividing the cylinderstotal clearance volume by the volume of the combustion chamber.) Now thefuel-air charge is ignited and the power, (3rd) stroke of piston 22takes place as the combusted gases expand. Near bottom dead center ofthe power stroke the exhaust valve(s) 17, 17′ opens and the cylinder 7is efficiently scavenged on the fourth piston stroke by positivedisplacement, after which exhaust valve(s) 17 closes.

This completes one cycle of the 4-stroke engine.

It can be seen that the later the point in the compression stroke thatpoint x is reached (the earlier or later the inlet valve is closed), thelower is the compression ratio of the engine and the less the charge isheated during compression. It can also be seen that the later thetemperature-density-adjusting charge is introduced, the less work willbe required of the engine to compress the charge, the later part ofwhich has received some compression already by an ancillary compressor2.

The Engine 100 ^(4-B) of FIG. 4-B

Referring now to FIG. 4-B there is shown a six cylinder 4-strokeinternal combustion engine similar in construction to the engine of FIG.4 with the exception that the engine of FIG. 4-B is so constructed andarranged that compressor 2 receives charge-air from manifold 14-Bthrough opening 8-B (shown in FIG. 7) and conduit 8 which air entersthrough common air intake duct 9. Intake runners 15 a-C to 15 f-Cdistributes the atmospheric pressure air to the intake valves 16-B ofeach power cylinder. This arrangement allows the provision of air tointake valves 16-A and 16-B at different pressure levels since thecharge-air from conduits 15-A is selectively pressurized by compressor2. The operation of the engine of FIG. 4-B is the same as that of theengine of FIG. 4.

The Engine 100 ⁵ of FIG. 5

Referring now to FIG. 5, there is shown a six cylinder 4-stroke internalcombustion engine 100 ⁵ similar to the engines 100 ⁴ of FIG. 4 andengine 100 ^(4-B) of FIG. 4-B with the exception that there are shownalternative ways that the dual atmospheric air inlets can be eliminated,preferably by providing the low pressure charge-air to intake valves16-B by way of conduits 15 a-D to 15 f-D all leading from the common airinlet conduit 8, or from an optional air manifold 35-M, situated betweeninlet conduit 8 and the inlet of conduits 15 a-D to 15 f-D, whichmanifold would also supply air to compressor 2 through conduit 8-A.Providing the low pressure charge-air to intake valve 16-B by way ofconduit 15-D, or by conduit 15-B (shown in phantom) would eliminate asecond air filter and air induction system and would work well witheither the first system described which involves closing the primaryintake valve 16-B during the intake stroke of the piston 22 oralternatively closing the primary intake valve 16-B during the 2nd orcompression stroke. Alternatively, as shown, the low pressure charge-aircan be supplied by placing a pressure-dropping valve 25 in conduit 15-Brouted for leading from the pressurized air conduit 15 (15-A) to the lowpressure cylinder inlet valve 16-B in order to drop the inducted airpressure down to the level that could be controlled by the system ofcompression ratio adjustment described herein, preferably down to 1.5to. 2.0 atmospheres (absolute pressure which is a boost of 0.5 to 1.0atmosphere) and perhaps down to atmospheric pressure.

The operation of the engine 100 ⁵ of FIG. 5 would be the same as theoperation of the engine 100 ⁴ of FIG. 4 although the low pressureprimary air supply is supplied differently. Because of noticeablesimilarities between the engine 100 ⁵ of FIG. 5 and that of FIG. 7,reference will be made as deemed helpful to FIG. 7 for certain commoncomponents.

During light-load operation of this 4-stroke cycle engine (FIG. 4, FIG.4-B and FIG. 5) such as vehicle cruising or light-load power generation,the secondary air charge is, alternatively, eliminated by disabling highpressure intake valve 16-A temporarily (there are several valvedisabling systems available. e.g., Eton, Cadillac. etc.) or air can beshut off to intake valve 16-A and the engine still produce greater fueleconomy and power than do conventional engines.

Alternatively and preferably, during light load operation such asvehicle cruising, the compressor 2 can be relieved of any compressionwork by closing the shutter valve 5 and opening the air bypass valve 6which circulates the air pumped back into the compressor 2 and then theair in intake conduits 15-A and 15-B or 1 5-D are approximately equal.Therefore, no supercharging takes place during this time. In oneembodiment, automatic valve 26, FIG. 6, prevents back-flow of air duringthe compression stroke if compression pressure in the cylinderapproximates or exceeds the pressure in conduit 15-A before the intakevalve 16-A closes.

For increased power the secondary air charge may be increased by shuttervalves 3 and 5 being preferably opened to direct the air charge tointercoolers 10, 11 and 12, which makes the charge denser and/or byincreasing the speed of compressor 2 or by adding a second stage ofpre-compression by compressor 1 in FIG. 7, the latter two actionsthereby pumping in more air on the backside. There is shown in FIG. 7that the primary compressor 2 is a Lysholm rotary type and a secondarycompressor 1 is a rotary compressor of the turbo type, although any typeof compressors can be used in the engines of this invention.

Referring now to FIG. 6 there is shown the same 4-stroke engine and asimilar operating system as described for the engines of FIG. 4, FIG.4-B, FIG. 5, FIG. 7 and FIG. 33, except that the engine of FIG. 6 has anadded feature in that the secondary intake valve 16-A has an auxiliaryvalve 26 which is automatic to prevent charge-air back-flow fromcylinder 7. This feature will prevent any back-flow from occurringduring the compression stroke of the engine of this invention. Thisfeature can also be used to establish the pressure ratio of the engine,either variable or constant. If secondary charge air is being receivedthrough intake valve 16-A, the intake valve 16-A can be kept open duringthe compression stroke to near top dead center of piston 22, sinceautomatic valve 26 closes at such time the pressure in cylinder 7approximates the pressure in intake runner conduit 15-A. Therefore, thepressure differential between cylinder 7 and intake runner 15-A willallow closure of automatic valve 26, even though intake valve 16-A maystill be open, allowing the pressure ratio of cylinder 7 to becontrolled by the pressure of any charge air coming through intakerunner 15-A, which in turn is controlled by valves 3, 5, and 6 andcompressor speed and perhaps a throttle valve, if present, for engineshaving a single stage of pre-compression. Valves 3, 4, 5 and 6 andcompressor speed and any throttle valve present would control thepressure ratios for engines having two stages of pre-compression. If nocharge is passing from intake valve 16-A, automatic valve 26 will bealready closed and the pressure ratio is set by the compression ratio ofthe engine and the density and temperature of the charge received bycylinder 7 through intake valve 16-B. The compression ratio is still setby the point in cylinder 7 that the primary intake valve 16-B is closed.The pressure ratio is set by the density and temperature of the airpresent in cylinder 7 whether it enters through valve 16-B, 16-A orboth, and by the compression ratio.

Any type of automatic valve can be used for item 26, perhaps aspring-retracted disc type which can be made of metal or ceramics.

The Engine 100 ⁷ of FIG. 7

Referring now to FIG. 7, there is shown a schematic drawing of a sixcylinder engine 100 ⁷ operating in a 4-stroke cycle. The engine issimilar in structure and operation to the 4-stroke engine of FIG. 4,FIG. 4-B and FIG. 5 and shows alternative air induction systemsutilizing air intake 9 (in phantom) or air intake 8′, or both. FIG. 7also shows three intercoolers 10, 11 and 12 and dual manifolds 13 and 14plus alternative intake manifold 14-B. The need for dual atmospheric airintake (8′ and 9 in FIG. 7) can be eliminated by providing air from port8-B of manifold 14-B directly to air intake conduit 8′ shownschematically, in FIG. 7.

One alternate air induction system shown in FIG. 7 suppliesunpressurized charge-air to intake valve 16-B of the engine of FIG. 4-Band of FIG. 7 by providing atmospheric pressure air to the intakerunners 15 a-C to 15 f-C leading from manifold 14-B in FIG. 4-B and FIG.7 which receives atmospheric air through induction port 9, and thendistributes the unpressurized air to intake valves 16-B of each powercylinder. Then, high pressure air enters through intake valve 16-A afterpiston 22 has reached point x during the compression stroke (the pointin which intake valve 16-B closes and compression begins). Intake valve16-A then closes, compression continues, fuel is added if not, presentand the charge is ignited near top dead center (TDC) and the power (3rd)stroke occurs.

A second alternate air induction system shown in FIG. 7 supplies lowpressure intake air as also shown in FIG. 5 of alternatively receivingair from high pressure conduit 15-A through conduit 15-B with theoptional pressure reducing valve 25, (shown in phantom in FIG. 5 andFIG. 7). The secondary high pressure air charge is injected by intakevalve 16-A at the same time or later that the piston 22 reaches thepoint at which the intake valve 16-B closes and compression begins.Intake valve 16-A then quickly closes, compression continues, fuel isadded if not present and the charge is ignited at the appropriate placefor the power (3rd) stroke.

A third alternate and preferred air induction system shown in FIG. 7supplies the primary air charge to intake valve 16-B as follows:Charge-air which has been pressurized to a low pressure by compressor 1,perhaps from 0.3 Bar to as much as 2 Bar or more, can selectively (andintermittently or continuously) be supplied to low pressure intakevalves 16-B of the engine of FIG. 7 by the way of conduit 32 leadingfrom conduit 110 to the intake valves (16 a-B through 16 f-B) whichconduit receives charge-air at atmospheric pressure or which has beenpressurized and in any case has had its temperature optimized, allcontrolled by compressor 1 and intercooler 10 with the charge-air pathsbeing controlled by valves 5 and 6 with the corresponding conduits. Inthis case the valve 33 is optional. After cylinder 7 has been chargedand the compression ratio established by the closing of intake valve16-B during the first or second stroke of piston 22, the high pressureintake valve 16-A opens on the compression stroke at the point whichvalve 16-B closes, to inject the dense, temperature adjusted air chargeand then it closes, as compression continues and near top dead center,fuel being present, the charge is ignited and the power (3rd) strokeoccurs. The use of this system also eliminates the need for dualatmosphere air intakes.

A fourth alternate air induction system shown in FIG. 7 supplies theprimary charge-air to the low pressure intake valves 16-B by havingcharge-air coming selectively from intake system 9, manifold 14-B andintake runners 15-C (shown in phantom) or from conduit 32 which woulddirect air to power cylinder 7 at whatever level of pressure andtemperature was needed at any particular time. With this arrangement,opening valve 33 at such a time that compressor 1 was compressing thecharge passing through it would have the effect of increasing thedensity of the primary charge-air which in this case could also have itstemperature as well as it pressure adjusted by compressor 1 and controlvalves 5 and 6. A one-way valve 34 would prevent the higher pressure airescaping through conduit 15-C. When less power was needed compressor 1could be “waste gated” by opening, partially or completely control valve6 and closing shutter valve 5. Alternatively, valve 33 could be closedby the engine control module (ECM) and the primary charge-air would bedrawn into cylinder 7 at atmospheric pressure through intake duct 9(shown in phantom). The piston 22 now begins its second stroke, theintake valve 16-B now closes, if not closed on the intake stroke, toestablish the compression ratio and in all cases the heavy secondarycharge enters through valve 16-A which opens at the time, or after,piston 22 has reached the point where intake valve 16-B had closed,valve 16-A then quickly closes, compression continues and the charge isignited near top dead center and the power (3rd) stroke occurs.

With this fourth alternate air induction system the low pressure intakevalve 16-B can (a) receive charge-air at atmospheric pressure or (b) canreceive charge-air which has been compressed and cooled through conduit32 or conduit 15-B. The high pressure intake valve 16-A (which opens atthe time, or later, at which compression begins) can receive charge-airwhich (a) has been compressed and cooled in a single stage by compressor1 or compressor 2, (b) has been compressed and cooled in two stages ormore to a very high density or (c) which has had its temperature andpressure adjusted by control valves 5 and 6, all in order to providebetter management of combustion characteristics in regard to power,torque and fuel economy requirements and in regard to emissions control.By incorporating an optional one-way valve (see valve 26 shown in FIG.6), the engines of FIG. 4, FIG. 4-B, FIG. 5 and FIG. 7 could have eithera constant or a variable pressure ratio, the charge density, pressure,temperature and turbulence and the time of closing of valve 26 beingcontrolled by valves 3, 5 and 6 and by compressor speed and by anythrottle valve present in engines having one stage of pre-compression,and by the addition of valve 4, in engines having two stages ofpre-compression. In either case the intake valve 16-A should be heldopen very late in the compression stroke, perhaps to near top deadcenter of piston 22.

One advantage to compressing the charge-air going to the low pressureintake valve 16-B in addition to highly compressing the secondary aircharge is that during much of the duty cycle of such engines the chargedensity could be dramatically increased while keeping peak pressures andtemperatures low, for high mean effective cylinder pressure. This systemcould provide all power necessary for vehicular travel in hilly countrywith perhaps the high pressure intake valves 16-A being deactivated by avalve deactivator indicated by 31 in FIG. 7, or by compressor 2 and/orcompressor 1 being partially or wholly bypassed by control valves 3 and4 and/or control valves 5 and 6 to vary the pressure and temperaturegoing into manifolds 13 and 14 and then to intake valves 16-A. Forutmost power, the valve deactivators could be turned off or eliminated.

Also shown in FIG. 7 is a suggested engine control system consisting ofan engine control module (ECM) 27, two shutter valves 3 and 5, two airbypass valves 4 and 6, the optional pressure reducing valves 25 (25 a-25f) on air conduits 15-B (15 a-B-15 f-B), and a scheme of controlling thepressure, temperature and density by controlling air bypass valves 4 and6 and shutter valves 3 and 5. As illustrated, air bypass valve 4 isclosed to allow compressor 2 to fully compress the charge and shuttervalve 3 is slightly open allowing part of the air to flow uncooled(hollow arrows) and some of the air cooled (solid arrows) to themanifolds 13 and 14, all of which could be controlled by the ECM 27 inorder to provide an air charge at optimum density, temperature andpressure. The hollow arrow 4-A in conduit 120 shows how ABV 4 can bepartially opened to allow some of the air to bypass and return tocompressor 2 in order to finely adjust the pressure of the secondary aircharge that is injected to adjust the charge density and temperature.Alternatively, all of the air charge can be directed through theintercoolers 10, 11 and 12 or through bypass conduits 121 and 122, tothe manifolds 13 and 14.

For high power with a low compression ratio and low polluting emissions,the air bypass valves (ABV) 4 and 6 are closed and the shutter valves 3and 5 would be opened so that the compressors 2 and 1 raise the pressureof the air charge which is directed by shutter valves 3 and 5 throughthe intercoolers for maximum density. During the intake stroke the lowpressure intake valve 16-B opens, piston 22 sucks in low pressure air,the intake valve 16-B closes before bottom dead center or after bottomdead center during the compression stroke. During the compressionstroke, at the point the intake valve 16-B closed or later, intake valve16-A opens to inject the secondary, dense, cooled air charge and thencloses. Compression continues for a low compression ratio. Fuel isadded, if not present, and the charge is ignited at the appropriatepoint near top dead center, (ignition can be before, at, or after topdead center) for the power (3rd) stroke with a large expansion ratiowith high torque, then exhaust valve(s) 17 open and the scavenging (4th)stroke occurs, after which exhaust valve(s) 17 closes.

In these designs, fuel can be carbureted, throttle body injected, portinjected, injected into the cylinder and can be introduced at any pointbetween the air intake and the piston crown. The fuel air mixture can bestratified, or from a stoichiometric to a very lean mixture for sparkignition, to a very rich mixture for diesel operation. The engine powercan be controlled by fuel metering alone or the air supply can beproperly adjusted to the proper fuel-air ratio by a throttle valve orcan be “metered” by control valves 4 and 6 when using two stages ofpre-compression and by control valve 4 when using a single stage ofpre-compression.

In any of the engines of this invention, the problem common to normalengines of incomplete mixing of fuel, air and residual gas, withconsequent variation in conditions at the ignition point is minimizedand in some cases eliminated by the late air charge injection at highvelocity. This problem, hereby addressed by the present invention, isextreme in current engines when gaseous fuel is injected directly intothe cylinder where the spark may occur in mixtures of varying fuel-airratios, hence with various rates of flame development.

(Concerning the importance of finding a solution to this particularproblem, engine researchers at Massachusetts Institute of Technologystate “The elimination of cycle-to-cycle variation in the combustionprocess would be an important contribution to improved [engine]performance. If all cycles were alike and equal to the average cycle,maximum cylinder pressures would be lower, efficiency would be greater,and most of all, the detonation limit would be higher, thus allowingappreciable increase in efficiency and/or mean effective cylinderpressure with a given fuel.”)

The cyclic variation spoken of is minimized and, potentially, eliminatedin the engine of each of the embodiments (including two-strokeembodiments and four-stroke embodiments) of the current invention by thesignificant swirl turbulence produced by the injection of high-pressureair. In addition, in any of the engines of this invention the swirlturbulence can be oriented tangentially to the cylinder wall byshrouding the inlet valve 16, and especially valve 16-A, or by the useof a one-way valve (such as valve 26 in FIG. 6 and FIG. 10). Evenengines that receive an air charge during the intake stroke of thepiston using a shrouded intake valve have a tendency to reduce unwantedcyclic variation and have a decrease in octane requirement and anincrease in knock-limited indicated mean effective (cylinder) pressure(klimep). The engine of the present invention, by injecting thecharge-air, especially through a shrouded valve during the compressionstroke, creates a much greater swirl turbulence to further eliminateunwanted cycle-to-cycle variation for cleaner, more complete combustionof the fuel.

The intake valve can rotate during operation and still have a flowtangential to the cylinder wall by using a conventional poppet valve andhaving the side of the valve head which is opposite the desireddirection of the air flow-being shrouded as it opens by a thickenedsection of the face of the engine's head forming a crescent shapedcollar or projection to direct the air flow in the desired directionwhile the valve is open.

In the diesel combustion system, the better mixing process of thepresent invention allows much richer fuel-air ratios for greatersmoke-limited power, and smoke and particulates are virtually eliminatedto an extremely rich fuel-air ratio.

The swirl turbulence produced by high pressure charge injection duringthe compression stroke is not dampened by the compression stroke and thelater the charge is injected, the smaller the volume of charge requiredto produce the desired swirl turbulence. In any reciprocating internalcombustion engine operating in accordance with the method of the presentinvention, a very high pressure, temperature-controlled air charge can,selectively, be injected tangentially oriented, very late in thecompression stroke, for example, just prior to, during or with fuelinjection and, with extremely high pressures, even during the combustionprocess.

Since the secondary air charge in the engine of FIG. 4 through FIG. 7,FIG. 9, FIG. 9-B and FIG. 15 through FIG. 20 is compressible to anextremely high level of pressure, the intake valve 16-A is, in alternateembodiments, replaced by a more controllable and fast-acting valve, suchas, but not limited to, a high-speed solenoid valve (not shown). Thisvalve is, preferably, operated either mechanically, electrically or byvacuum and is, preferably, controlled by an engine control module (ECM)as illustrated in FIG. 7, FIG. 9-B, FIG. 15 through FIG. 20 and FIG. 33.In this system the secondary air charge can, selectively, be injectedvery late in the compression stroke of piston 22 in order to increasecharge density, and swirl turbulence, and to reduce peak and overallcombustion temperatures and to lessen the production of pollutingemissions. The injection could be performed in a tangentially orientedfashion. This would greatly increase swirl turbulence and preventundesirable cyclic variations which are common in normal engines andmost troubling in gaseous or diesel fueled engines.

The use of this system should result in lower maximum cylinder pressuresand temperatures. Efficiency should be greater and the detonation limithigher, thus allowing an appreciable increase in efficiency and meaneffective cylinder pressure with a given fuel. All of the engines ofthis invention operate with a more complete expansion process ascompared to the typical prior art engines, thereby providing furtherimprovements in efficiency and emissions characteristics.

In accordance with the present invention, the 4-stroke engines of thepresent invention (for example, FIG. 1, FIG. 2, FIG. 3, FIG. 4, FIG.4-B, FIG. 5, FIG. 7 and FIG. 33) are designed, as are the 2-strokeengines of the present invention (for example, FIGS. 8-11, 25 and 33),to use an expansion ratio larger than the compression ratio. In order toaccomplish this result, the expansion ratio is set by selecting theappropriate combustion-chamber volume and the compression ratio isreduced below this value by very early or very late closing of the inletvalve.

The Engine 100 ⁸ of FIG. 8

Referring now to FIG. 8, there is shown a six cylinder reciprocatinginternal combustion engine 100 ⁸ for gasoline, diesel, alcohol, naturalgas, hydrogen or hybrid dual-fuel operation and having six cylinders 7a-7 f (only one, 7 f, is shown in a sectional view) in which the pistons22 a-22 f are arranged to reciprocate. Another cylinder is indicatedonly by the presence of the lower end of the cylinder liner 7 a. Acut-a-way view shows a double-acting compressor cylinder 1. Pistons 22a-22 f are connected to a common crankshaft 20 in a conventional mannerby means of connecting rods 19 a-19 f, respectively. The engine 100 ⁸ ofFIG. 8 is adapted to operate in a 2-stroke cycle so as to produce sixpower strokes per revolution of the crankshaft 20. To this endcompressor 1 takes in an air charge at atmospheric pressure, (oralternatively an air charge which previously had been subjected tocompression to a higher pressure via an admission control valve 6through an intake conduit 102, leading from compressor 2 by way ofbypass control valve 6 and shutter valve 5 and bypass conduit 104 orthrough the intercooler 10). During operation of the engine of FIG. 8,the air charge is compressed within the compressor 1 by its associatedpiston 131, and the compressed charge is forced through an outlet into ahigh-pressure transfer conduit 109 which leads to bypass valve 3 whichis constructed and arranged to channel the compressed charge throughintercoolers 11 and 12 or through bypass conduit 111 in response tosignals from the engine control module (ECM) 27. This module directs thedegree of compression, the amount and the direction of the flow of thecompressed charge through the intercooler and/or the bypass conduit intomanifolds 13 and 14. Manifolds 13 and 14 are constructed and arranged todistribute the compressed charge by means of branch intake conduits 15a-15 f and to inlet valves 16 and 16′, and to the remaining five powercylinders. Alternatively, an ancillary compressor 2 receives atmosphericair through inlet opening 8, pre-compresses the air charge into conduit101 leading to control valve 5 which in response to signals from ECM 27will direct the compressed charge through intercooler 10 or bypassconduit 104 to compressor 1. The ECM 27 can also control valves 4 and 6to direct part or all of the charge passing through compressors 1 and 2back through conduits 120 and 103 in order to adjust the amount ofcompression of compressors 1 and 2 ranging in either or both compressorsfrom full compression to no compression, thus during light-loadoperation either compressor 1 or compressor 2 could supply the neededcompressed air to the cylinders.

The Engine 100 ⁸ of FIG. 8 has camshafts 21 which are arranged to bedriven at the same speed as the crankshaft in order to supply oneworking stroke per revolution for the power pistons. The reciprocatingcompressor can have one or more double-acting cylinders one is pictured1 and can have more than one stage of compression, and the crankshaft 20would supply two working strokes per revolution, for one or morecompressors, as described hereinafter. The reciprocating compressorcould alternatively be driven by a short crankshaft which would berotated by a step-up gear on the main crankshaft driving a smaller gearon the ancillary crankshaft. The ancillary rotary compressor 2 could bedriven by V-pulley operated by a ribbed V-belt and could have a step-upgear between the V-pulley and the compressor drive shaft. The rotarycompressor 2 could also have a variable speed drive as in some aircraftengines.

Description of the Operation of the Engine 100 ⁸ of FIG. 8.

Charge-air is induced into the inlet opening 8 of compressor 2, fromthere it passes through the compressor 2 where the charge is theninducted into conduit 101 to shutter valve 5 where the charge isdirected either through intercooler 10 or through air bypass valve 6where a portion or all of the charge can be directed back through thecompressor 2 where the charge is re-circulated without compression, orvalve 6 can direct the air charge into the inlet of compressor 1 wherethe air charge is pumped out the outlet duct of compressor 1 which leadsto shutter valve 3 where the charge is directed either throughintercoolers 11 and 12 or through air bypass valve 4 or a portionthrough both, leading to manifolds 13 and 14 which distribute thecharge-air to the intake valves 16 and to the intake valve of each powercylinder 7 of the engine 100 ⁸. (Bypass valve 4 can direct part or allof the air charge to manifolds 13 and 14, or can recirculate part or allof the air charge through conduit 120 back to conduit 106 and into theinlet of compressor 1.) The engine control module (ECM) 27 controlsvalves 3, 4, 5, and 6, in order to adjust the pressure, temperature anddensity of the charge that is inducted into the engine's combustionchambers 130. The same ECM 27 can control a variable-valve-happeningcontrol system to adjust the time of opening and closing of the inletvalves 16 and exhaust valves 17 of the power cylinders in relationshipto the angle of rotation of crankshaft 20, in order to adjust thecompression ratio and charge density of the engine for optimumperformance in regard to power, torque, fuel economy and characteristicsof fuel being supplied.

The Operation of the Power Cylinder 7 is in this Manner:

Alternate Method 1:

Near the end of the power stroke in cylinder 7, the exhaust valve(s) 17,17′ open and, with the exhaust valve still open, the piston 22 beginsthe second or exhaust stroke. During the exhaust stroke, perhaps asearly as 70° to 60° before top dead center the exhaust valves 17, 17′close. At the point the exhaust valves are closed the compression ratiois established, the intake valves 16, 16′ are opened at that point orlater in the compression stroke, the compressed air and/or air-fuelcharge is injected into the combustion chamber 130 of the power cylinder7, intake valve 16, 16′ closes at perhaps 60° before top dead center,with the swirl and squish turbulence accompanying the high-pressure airinjection, the piston 22 continues towards the end of its stroke thuscompressing the charge producing a very low compression ratio, which canbe as low as 2:1. If fuel is not already present as a mixture, fuel isinjected into the incoming air stream or it is injected into apre-combustion chamber or directly into the combustion chamber afterclosure of he intake valve. The fuel can be injected into the midst ofthe charge swirl for a stratified charge combustion process, or it canbe injected onto a glow plug if diesel fuel is to be ignited. Thefuel-air mix is ignited by compression or spark, the latter at theopportune time for greatest efficiency and/or power. Generally, the fuelwould be injected and ignited before top dead center of the piston. Thefuel can be injected later and perhaps continuously during the earlypart of the expansion stroke for a mostly constant-pressure combustionprocess and especially for diesel fuel. The fuel air mixture is ignitedpreferably before the piston reaches top dead center and the combustedcharge expands against the piston as it moves toward bottom dead center.At near bottom dead center of the piston stroke, the exhaust valve(s) isopened and the exhausted mixture is scavenged by positive displacementby the piston 22 during the scavenging stroke. If the intake valve 16,16′ is opened earlier some valve overlap with the exhaust valve may berequired for scavenging. If the intake valves 16, 16′ are opened late novalve overlap would be needed, exhaust valve(s) 17, 17′ closing atapproximately the same time that intake valve(s) 16, 16′ open. Theexpansion ratio of the engine could be about 19:1, for diesel fuel, 14:1for gaseous fuel or gasoline, which expansion ratio is established bydividing the cylinder displacement volume by the volume of thecombustion chamber.

Alternate Operation Method 2:

Near the end of the power stroke in cylinder 7 the exhaust valve(s) 17,17′ open, and with exhaust valve 17, 17′ still open, begins its secondor scavenging-charging stroke. At a point near mid-stroke, (e.g., about90° before top dead center,) the exhaust valve 17, 17 ′ still beingopen, the intake valve opens with a small valve overlap to admit highpressure scavenging and charging air. One or more intake valves 16 canbe recessed, as in item 30 in FIG. 11, in order to direct the firstinlet air down and along the cylinder 7 wall in order to loop-scavengethe cylinder during the very small overlap of valves 16, 16′ and 17,17′. The exhaust valve 17, 17′ remains open to the point at whichcompression should begin and then receives the air charge as it closes,intake valve(s) 16, 16′ closing soon after, with the cylinder adequatelyscavenged and charged with temperature-adjusted fresh air now at highpressure. The piston 22 continues its stroke to compress the chargeproducing a low compression ratio, ideally 13:1 to 4:1, depending on thetype of fuel used. The compression ratio is established by the point inthe stroke of piston 22 in which the exhaust valve(s) 17, 17′ closes,and is calculated when the remaining displaced volume of the cylinder isdivided by the volume of the combustion chamber.

As piston 22 continues to rise from point x, where the exhaust valvecloses establishing the compression ratio, and where compression of thecharge started, the pressure starts to rise at the same point. The densecooled air charge with the short compression stroke will produce a lowcompression ratio with a very heavy charge, with low maximum cylinderpressure but with high effective mean cylinder pressure for great torqueand power.

The pressure ratio will be established by the density, pressure andtemperature of the incoming charge, the length of time inlet valve(s)16, 16′ are open and the point the exhaust valve(s) 17, 17′ closes. Thelater the exhaust valves 17, 17′ close, the less the charge-air expandsafter injection, the less work is required to compress the charge andthe less overlap of inlet and exhaust valve is required and the lower isthe compression ratio.

At some point, perhaps as early as 150-120 degrees before piston topdead center position, cylinder 7 would be adequately scavenged and theexhaust valve 17, 17′ could be closed before, or no later than, the timethe intake valves 16, 16′ are opened to admit, in this case, the entireair charge, most of the exhausted gases having been displaced byscavenging. (In some cases some residual exhaust gases are beneficialand experiments will show at what point both intake and exhaust valvescan be closed without any overlap.) In this instance the “effective”compression ratio could be as low as 3:1 or even 2:1, again producinglow maximum cylinder pressure and temperature but with high meaneffective pressure. Fuel can be injected as early as at the point theexhaust valve closes and can be as early as about 150°-120° before theend of the compression stroke. The fuel-air mixture is ignited before,at, or after, top dead center and the expansion (2nd) stroke takesplace. The expansion ratio is established by dividing the cylinder'sdisplaced volume by the combustion chamber volume and could be about19:1 for diesel applications, and 14:1 for gasoline or gaseous fuels.

An engine control module (EC4) 27 can manage temperatures and densitiesof the charge being introduced into the cylinder 7 or combustion chamber130 and the timing of the inlet into the combustion chamber and can thusadjust charge densities, turbulence, temperatures and pressuresproviding a means of restraining peak temperatures and pressures yetwith a mean effective cylinder pressure higher than in a normal engine,when needed and further providing for lower levels of unwanted pollutingemissions.

A suggested light-load, fuel efficient operation system as indicated online B(bp) in FIG. 13, would be thus: A nominal compression ratio of13:1 could be chosen, with an expansion ratio of 19:1. The latter wouldestablish the volume of the combustion chamber, the former wouldestablish the maximum charge pressure (not maximum cylinder pressure),about 530 psi when compressed adiabatically. The ECM 27 would signalshutter valves 5 and air bypass control valve 6 to re-circulate the airbeing pumped through compressor 2, back through the compressor 2 withoutbeing compressed or for any type compressor, open a waste-gate valve tobypass the compressor. Shutter valve 5 bypasses the intercooler 10 anddirects the charge into the inlet of compressor 1. Compressor 1 wouldcompress the charge adiabatically to say, 7:1 compression ratio. ECM 27controls would bypass intercoolers 11 and 12 and introduce the chargeinto manifolds 13 and 14 with the heat-of-compression retained. If theexhaust valves 17, 17′ are closed and the inlet valve 16, 16′ ofcylinder 7 are opened near the end of the compression stroke of piston22 the effective compression ratio can be as low as 2:1, producing a“nominal” compression ratio of 14:1. (If the exhaust valves 17, 17′ areclosed and the inlet valve 16, 16′ are opened earlier in the exhauststroke, the injected charge-air should be of lower pressure and the“effective” compression ratio, that in-cylinder compression producingheat, would be greater. If the intake valves 16, 16′ opened atmid-stroke, after exhaust valves 17, 17′ close, and a nominalcompression ratio of 13:1 were desired with an effective compressionratio of 4:1, then the charge introduced into the cylinder at mid-strokeshould be compressed 4:1.) The uncooled charge is then compressed in thecylinder with an effective compression ratio of 4:1, and in either case,with a pressure of about 530 psi and a temperature above 900° F. Thefuel/air charge is then ignited and expanded against the piston to thefull volume of the power cylinder with an expansion ratio of 19:1.

At such a time that great power was required, the ECM 27 could signalthe air bypass valve 4 and 6 to close. Compressor 2 then begins tocompress the air charge to a higher pressure, at the same time ECM 27would open shutter valves 3 and 5 to send the charge-air through theintercoolers 10, 11 and 12. Therefore, as the charge-air is cooled, andcould be to as low as 150°-200° F., more air is now pumped into theengine on the back side by the additional compression stage 2, toprevent a substantial pressure drop in the charge-air due to the coolingof the charge before combustion. The air charge in the combustionchamber is now compressed 2:1 (line B(ic), FIG. 13) and is maintainednear the design pressure, in this case about 500-530 psi, althoughcooled, to significantly increase the density of the charge and thetorque and power of the engine. The cooler air charge provides lowerpeak temperature and pressure and coupled with the high turbulencecauses production of less unburned hydrocarbons, NO_(x) and otherpolluting emissions and with smoke and particulates being virtuallyeliminated to a very rich fuel-air mixture. The air-fuel charge is nowignited and expanded to the full volume of the cylinder with anexpansion ratio of 19:1 although the effective compression ratio is only2:1 (see line B (ic) in FIG. 13).

With either operation scheme the engine can be supercharged to a higherstate than can conventional engines because in most cases the inletvalve is closed at the time of combustion chamber charging and a coolerair charge prevents detonation and reduces polluting emissions. Also inmost cases residence time of the fuel is less than that required forpre-knock conditions to occur.

When less power is needed, as during vehicle cruising or light-loadpower generation, the engine operation could revert to light-loadoperation, e.g., one stage of compression could be cut out and the firstcooler 10 bypassed by the air charge being re-circulated by shuttervalve 5 and by bypass valve 6. Shutter valve 3 and air bypass valve 4could direct all of the charge from compressor 1 passed intercoolers 11and 12 with the heat-of-compression retained, into manifolds 13 and 14and to the cylinder for the less dense, more fuel efficient operationmode.

Still referring to FIG. 8, there is shown a view of a cylinder head ofthe engine of FIG. 8 through FIG. 11 and FIG. 25, showing optionalpressure balanced intake valves with cooling being provided by conduitswith intake conduit 29 and outlet conduit 29′, one-way valves (notshown) which allow expansions 28 on the valve stems, as they reciprocatewith intake valves 16 to pump a cooling and lubricating oil or oil-airmixture through the spaces above the valve stem expansions.

Pressure-balanced intake valves 16, 16′ in FIGS. 8, 11, and 25, and 16-Ain FIGS. 9 and 10 provide for rapid intake valve closure and allowslarge non-restricting intake valves and smaller than normal valve returnsprings. (When the intake valve is opened, pressure equilibrium almostimmediately takes place below the valve head within the combustionchamber and above the valve head within the intake runner, then thepressure in the intake runner acting on the piston-like arrangement onthe valve stem tends to cause the valve stem to follow the down-slope ofthe cam profile for rapid valve closure. Also, a new “Magnavox” pressureoperated, “square wave” intake valve could be used in the engines ofthis invention.)

The operation of the pressure balanced intake valves is in this manner:

The pressure balanced intake valves have expansions 28 on the valvestems, the lower surface of which are exposed to gases in conduit 15A.When the valve stem is depressed by a cam 21 and intake valve(s) 16opens in FIG. 8 through FIG. 11, or FIG. 25 any pressure in conduit 15Ais equilibrated with pressure in the combustion chamber and at that timethe only reactive force is by any pressure in conduit 15A which isagainst the underside of valve stems expansions 28, causing a rapidclosure of the valve. One-way valves (not shown) on inlet and outletchannels 29 and 29′ are preferably provided for oil or oil-air mixtureinduction through spaces above expansions 28, and alternatively throughthe valve stem expansions 28. The oil inlet could be at a low point inthe cylinder head where oil would collect to supply the cooling system.Alternatively, oil inlet line 29 could be connected to an oil or oil-airmix supply line. The inlet conduit 29 and the exit conduit 29′ from thecooling system would be fitted with one-way valves and the exit conduit29′ could be higher than the inlet conduit 29 or could be connected toan oil discharge line leading to the engine oil reservoir. The valvestem expansions 28 could also have a channel through them with a one-wayvalve on each side. Since historically exhaust valves have beendifficult to cool, this same system would provide adequate cooling forthe exhaust valves even though there is not great pressure in theexhaust conduit. This system would then be applied to exhaust valves 17from which exhaust ports 18 originate, or to the exhaust valves of anyengine to provide long life for the exhaust valves and the valve seats.

On large engines the lines from the pumps described here can convergedinto larger lines and the oil pumping provided by them could replace theconventional oil pump on said engine.

The Engine 100 ⁹ of FIG. 9

Referring now to FIG. 9, there is shown a six cylinder reciprocatinginternal combustion engine having one atmospheric air intake, in whichall of the cylinders 7 a-7 f (only one (7 f) is shown in a sectionalview) and associated pistons 22 a-22 f operate in a 2-stroke cycle andall power cylinders are used so as to produce six power strokes perrevolution of crankshaft 20 for producing power to a common crankshaft20 via connecting rods 19 a-19 f, respectively. A primary compressor 1,in this figure a double-acting reciprocating type, is shown which, withair conduits as shown, supplies pressurized air to one or more cylinderintake valves 16-A and 16-B (the latter only if a primary charge tovalve 16-B comes from conduit 15). A secondary compressor 2 of theLysholm type is shown in series with compressor 1. An air inlet 8 andassociated compressors 1 and/or 2 with inlet conduits and manifolds 13and 14 supply charge-air, which has been compressed to a higher thanatmospheric pressure, to the air intake runner 15-A and intake valve16-A to cylinder 7. A second conduit 32 directs an air charge fromconduit 110 through optional shut-off valve 33 to intake valve 16-B tosupply lower pressure air to the same cylinder. Alternatively a secondconduit 15-B from conduit 15-A can be fitted with a pressure controlvalve 25 (both in phantom) and can direct the lower pressure air chargeto the intake valve 16-B. Intercoolers 10, 11 and 12 and control valves3, 4 5 and 6 are used to help control the density, weight, temperatureand pressure of the charge air. The intake valves are timed to controlthe compression ratio of the engine. The combustion chambers are sizedto establish the expansion ratio of the engine.

The engine of FIG. 9, FIG. 11 and FIG. 25 have cam shafts 21 fitted withcams and are arranged to rotate at engine crankshaft speed in order tosupply one power stroke for each power piston for each crankshaftrotation.

The engine 100 ⁹ shown in FIG. 9 is characterized by a more completeexpansion process and a lower compression ratio than typical engines,and is capable of producing a combustion charge varying in weight fromlighter-than-normal to heavier-than-normal and capable of selectivelyproviding a mean effective cylinder pressure higher than can theconventional arrangement in normal engines with similar or lower maximumcylinder pressure. Engine control module (ECM) 27 and variable valves 3,4, 5 and 6 on conduits as shown provide a system for controlling thecharge pressure, density, temperature, and mean and peak pressure withinthe cylinder which allows greater fuel economy, production of greaterpower and torque at all RPM, with low polluting emissions for both sparkand compression ignited engines. In alternate embodiments, a variablevalve timing system with the ECM 27 can also control the time of openingand closing of the intake valves 16-A or 16-B or both, to furtherprovide an improved management of conditions in the combustion chamberto allow for a flatter torque curve, higher power and with low levels ofboth fuel consumption and polluting emissions.

Brief Description of Operation of Engine 100 ⁹ Shown in FIG. 9

The new cycle engine 100 ⁹ of FIG. 9 is a high efficiency engine thatattains both high power and torque, with low fuel consumption and lowpolluting emissions.

The new cycle is an external compression type combustion cycle. In thiscycle part of the intake air (all of which is compressed in the powercylinders in conventional engines) is compressed by at least oneancillary compressor. The temperature rise at the end of compression canbe suppressed by use of air coolers, which cools the compressed air, andby a shorter compression stroke.

During operation air is supplied to an intake valve 16-B of the powercylinder 7 which has been increased in pressure by perhaps one-third toone atmosphere or more through an air intake conduit 32 leading fromancillary compressor 2, or the air enters by conduit 15-B and a pressurecontrol valve 25. A second air conduit 15A selectively suppliescharge-air at a higher pressure to a second intake valve 16-A leading tothe same power cylinder 7. (In this design the intake valve 16-B admitsthe low pressure air after exhaust valves 17 open near bottom deadcenter in the power stroke, and exhaust blowdown has occurred.) Exhaustblowdown occurs after exhaust valve(s) 17 open and now intake valve 16-Bopens and closes quickly to inject low pressure scavenging air. Thecylinder 7 is further scavenged by loop scavenging as piston 22 beginsits compression stroke. Intake valve 16-B is now closed and piston 22rises in the compression stroke to the point where compression shouldbegin at which point exhaust valve 17 closes sealing cylinder 7 andestablishing the compression ratio. Compression continues and at neartop dead center, at a point deemed appropriate, fuel being present, thecharge is ignited by spark or compression and the power stroke takesplace.

When more power is desired, a secondary air charge from conduit 15-A canbe introduced into the power cylinder at the time of, or after closureof exhaust valve(s) 17 a during the compression stroke, by intake valve16-A which introduces a higher pressure air charge, and quickly closes,in order to increase the charge density. Alternatively, the primary aircharge may be boosted to a higher pressure by adjusting air bypass valve6 to send more air through compressor 2, by increasing the speed ofcompressor 2 or by changing the setting on the control valve 25 on theconduit 15-B which alternatively supplies the low pressure primary aircharge to intake valve 16-B. The temperature, pressure, amount and pointof injection of a secondary charge, if added, is adjusted to produce thedesired results.

For light-load operation an intake valve disabler 31 (there are severalon the market, for example, Eaton Corp. and Cadillac) can disable intakevalve 16-A when light-load operation does not require a high meaneffective cylinder pressure. Alternatively, during the time the lowpressure air to intake valve 16-B is supplied by conduit 15-B the airbypass valve (ABV) 6 can be opened to re-circulate some of thecharge-air back through the compressor 2 in order to relieve thecompressor of compression work during light-load operation.Additionally, and preferably, air bypass valve 4 can re-circulate partor all of the air pumped by compressor 1 back to the inlet of compressor1 on demand in order to reduce pressure and density of the secondarycharge going through intake valve 16-A.

One suggested, preferred method of operation of the new-cycle engine 100⁹ is thus:

-   -   1. Intake air at greater than atmospheric pressure that has been        compressed by at least one compressor 2 and has had its        temperature adjusted by bypass systems or charge-air cooler 10,        is introduced into the cylinder 7 through intake valve 16-B,        which is opened by a small lobe on cam 21-B at near bottom dead        center, at the end of the power stroke (perhaps at bottom dead        center) after exhaust valve(s) 17, 17′ have opened earlier say,        at 40° before bottom dead center, for exhaust blowdown. The        exhaust valves remain open after bottom dead center for further        scavenging of the cylinder 7. The intake valve 16-B closes at        near bottom dead center.    -   1. After the power stroke is complete and cylinder 7 is filled        with fresh charge, the exhaust valve(s) 17 is left open for a        period of time after the piston has passed bottom dead center        (with intake valve 16-B now closed) in order to further scavenge        the power cylinder with the fresh air charge present and        further, in order to establish a low compression ratio of the        engine, the compression ratio being established by the displaced        cylinder volume remaining at the point of the exhaust valve 17        closure, being divided by the volume of the combustion chamber.    -   3. With the cylinder 7 now filled with fresh air, the        compression (2nd) stroke continues and, at some point the        exhaust valve 17 is closed and compression begins for a small        compression ratio. This makes it possible to lessen the        temperature rise during the compression stroke. Compression        continues, fuel is added if not present, and the charge is fired        a the appropriate point near top dead center and the power        stroke occurs.    -   4. (a) Alternatively, when greater power is required, a        secondary compressed, temperature-adjusted air charge is        injected into the cylinder 7 by intake valve 16-A opening and        quickly closing during the compression stroke at the point at        which the exhaust valve closes, or later in the stroke, to        produce a more dense charge in order to provide the torque and        power desired of the engine.    -   (b) When even greater power is required, the secondary air        charge can be increased in density and weight by being passed        through one or more intercoolers 10, 11 and 12 and by increasing        compressor speed or by cutting in another stage of auxiliary        compression or by passing more of the charge air through the        operational compressors.    -   5. Near bottom dead center of the piston position, exhaust        valves 17, 17′ open and the cylinder is efficiently scavenged by        blowdown and by the air injected by primary intake valve 16-B.        Detailed Description of the Operation of the Engine 100 ⁹ of        FIG. 9

Near the end of the power (1st) stroke of the piston 22, perhaps atabout 40° before bottom dead center position of piston 22, the exhaustvalves 17 open for exhaust blowdown, shortly after low pressure airflows through air conduit 32 from conduit 106 and optional shut-offvalve 33 and compressor 2 or alternatively through air conduit 15-Bsupplied by a pressure regulator valve 25 from compressed air line 15-A(as shown in FIG. 9, and FIG. 10), through an intake valve 16B into thecylinder 7. Intake valve 16-B closes shortly after bottom dead centeror, perhaps at bottom dead center. Exhaust valves 17 remain open duringthe first part of the compression (2nd) stroke of piston 22. Thecylinder 7 is now efficiently scavenged by blowdown and by loopscavenging and at any point during the compression stroke, the cylinder7, now filled with fresh air, the exhaust valves 17, 17′ can close. Butsince a low compression ratio is desired, the exhaust valves 17, 17′ canbe held open until the piston has reached the point that is desired toestablish the compression ratio. At, or after the time exhaust valves 17a and 17 a are closed, a secondary charge of high pressure, temperatureadjusted air which has been compressed by a compressor(s) can beinjected by intake valve 16-A into the same cylinder, after which intakevalve 16-A closes. In addition, when very high torque and power isneeded, the density of the secondary charge-air can be greatly increasedby cutting-in compressor 2 or by increasing the speed of compressor 2,if already compressing, as in FIG. 9, directing more air throughcompressors 1 and/or 2 by valves 4 and/or 6, and by routing the chargewholly or in part through intercoolers 10, 11 and 12.

In this system, regardless of the point the exhaust valve is closed toestablish the compression ratio, the primary fresh air charge trapped inthe cylinder 7 will be lighter than normal and the compression ratiowill be lower than normal, therefore, if needed, a highly compressed,temperature adjusted air charge can be injected at exhaust valve closureor later in the stroke, to provide a heavier than normal charge but withthe temperature rise being restrained by the cooled charge and the shortcompression stroke. This produces a greater than normal mean effectivecylinder pressure when combusted for great torque and power but stillwith an expansion ratio greater than the compression ratio.

For light-load operation a shut-off valve, or a valve disabler 31 (inphantom) on the high pressure intake valve could temporarily restrainthe intake air, or hold the valve 16-A closed. This would add to thefuel economy of the engine. Alternatively, if compressor 2 is notsupplying air to conduit 32 and intake valve 16-B, during light-loadoperation the shutter valve 5 could be closed and the air bypass valve 6can be opened so that air pumped by compressor 2 would be returned inpart or wholly to the inlet conduit of the compressor 2 with little orno compression taking place there.

An ancillary automatic intake valve 26, FIG. 10, can be arranged asshown in FIG. 10, to prevent any back-flow of charge-air into conduit15-A if the cylinder 7 pressure should approximate or exceed thepressure in conduit 15-A during the compression stroke of piston 22before the closure of intake valve 16-A.

Alternatively, the ancillary automatic valve 26 of FIG. 10 could be usedto provide a constant or a variable pressure ratio in cylinder 7. Inthis case valve 16-A would be kept open to near top dead center and theclosure time of valve 26 would be adjusted by the pressure differentialin cylinder 7, controlled by valves 3, 4, 5 and 6 by compressor(s)output and by any throttle valve present. The automatic valve 26 couldbe of the spring-retracted disc type and could be fabricated of metal orceramics.

Fuel can be carbureted, injected in a throttle body 56, shown in FIG. 15through FIG. 17 and item 56 in FIG. 19 and FIG. 20, or the fuel can beinjected into the inlet stream of air, injected into a pre-combustionchamber (similar to that seen in FIG. 21) or, injected through intakevalves 16-A, or it may be injected directly into the combustion chamberat point x during the exhaust-compression stroke, at the time or afterthe piston 22 has passed point x in the compression stroke. The fuel canalso be injected later and in the case of diesel operation can beinjected at the usual point for diesel oil injection, perhaps into apre-combustion chamber or directly into the combustion chamber, perhapsas FIG. 21, or directly onto a glow plug. After thetemperature-and-density-adjusting-air charge has been injected, if used,compression of the charge continues and with fuel present, is ignited atthe opportune time for the expansion stroke. (The compression ratio isestablished by the displaced volume of the cylinder remaining afterpoint x has been reached, being divided by the volume of the combustionchamber. The expansion ratio is determined by dividing the cylinderstotal clearance volume by the volume of the combustion chamber.)

Now the fuel-air charge is ignited and the power (2nd) stroke of piston22 takes place as the combusted gases expand. Near bottom dead center ofthe power stroke the exhaust valve(s) 17, 17′ open and the cylinder 7 isefficiently scavenged by blowdown and by loop scavenging at the end ofthe power stroke and largely during the piston 22 turnaround time.

It can be seen that the later the point in the compression stroke thatpoint x is reached (the later the exhaust valve is closed), the lower isthe compression ratio of the engine and the less the charge is heatedduring compression.

It can also be seen that the later the temperature-density-adjustingcharge is introduced, the less work will be required of the engine tocompress the charge, the later part of which has received somecompression already by compressor 1 and or by an ancillary compressor 2.In some cases where the load is light and fuel economy important theancillary compressor could be bypassed with the secondary air chargeperhaps eliminated temporarily and the total charge weight could be lessthan that of a conventional engine and with the extended expansion ratioproduce even better fuel economy.

During light-load operation of this 2-stroke cycle engine (FIG. 9 andFIG. 9-B) such as vehicle cruising or light-load power generation, thesecondary air charge can be eliminated by disabling high pressure intakevalve 16-A temporarily (several valve disabling systems Eton, Cadillac,etc.) or air can be shut off to intake valve 16-A and the engine stillproduce greater fuel economy and power with the air charge beingsupplied by compressor 2 or 1 through conduits 15-A, 110, 32 and intakevalve 16-B.

The Engine 100 ^(9-B) of FIG. 9-B

FIG. 9-B is a schematic representation of a six-cylinder reciprocatinginternal combustion engine 100 ^(9-B) which is for the most partidentical to the engine 100 ⁹ of FIG. 9. The characteristics andoperation and structure of the engine 100 ^(9-B) of FIG. 9-B aresubstantially similar to the engine 100 ⁹ of FIG. 9 and, except asnecessary to point out specific points of distinction, suchcharacteristics, operation and structure are not repeated here.Reference should be made to the sections on characteristics, structureand operations (both brief and detailed) previously presented withrespect to the engine 100 ⁹ of FIG. 9.

The major point of distinction between engine 100 ⁹ and engine 100_(9-B) is that engine 100 _(9-B) represents an embodiment of the engine100 ⁹ wherein the compressors 1,2 are of alternate types. That is, in100 ^(9-B), the primary compressor 1 is shown as a Lysholm rotarycompressor (as opposed to the reciprocating-type compressor of engine100 ⁹) and the secondary compressor 2 is of the turbo-type (as opposedto the Lysholm-type of 100 ⁹). Although conduit 32 from conduit 110(designated as 106 in FIG. 9) and optional shut-off valve 33 is shownsupplying intake valves 16-B of only two cylinders of the engine, it isunderstood that other intake runners (not shown) distribute air fromconduit 110 to the remainder of the intake valves 16-B of the engine, orthat conduit 32 supplies an “air box” or manifolds which distribute theair to all of the intake valves 16-B.

Referring now to FIG. 10 there is shown the same engine and the sameoperating system as described for the engines of FIG. 9 and FIG. 9-B,but has an optional added feature in that the secondary intake valve16-A has an ancillary valve 26 which is automatic to prevent charge-airback-flow from cylinder 7. This feature will prevent any back-flow fromoccurring during the compression stroke of the engine of this invention,should the cylinder pressure approximate or exceed the pressure inconduit 15-A before the intake valve 16-A was fully closed. (Thisoptional automatic valve 26 could be of the spring-retracted disc type,or could be any type of one-way valve.) An automatic valve at this placecould be used to regulate the pressure ratio in cylinder 7 during thecompression of the charge. In this case intake valve 16-A could be keptopen to near top dead center, valve 26 automatically closing the intakebelow valve 16-A during compression, ignition and power stroke of thecharge. Furthermore, the use of automatic valve 26 would allow thepressure ratio of the engine to be adjusted by simply adjusting thepressure in conduit 15-A, with intake valve 16-A being kept open to neartop dead center of piston 22. The ancillary valve 26, if present, wouldalso impart a tangentially oriented swirl turbulence to the combustioncharge as would also, shrouding of intake valve 16-A.

The Engine 100 ¹¹ of FIG. 11

Referring now to FIG. 11, there is shown a six cylinder reciprocatinginternal combustion engine 100 ¹¹ with one atmospheric air intake, inwhich all of the cylinders 7 a-7 f (only one (7 f) of which is shown ina sectional view) and associated pistons 22 a-22 f operate in a 2-strokecycle and all power cylinders are used for producing power to a commoncrankshaft 20 via connecting rods 19 a-19 f respectively. A primarycompressor 1, in this figure a double-acting reciprocating type, isshown which, with an air conduits, as shown, supplies pressurized air toone or more cylinder intake valves 16 a and 16 b. A secondary compressor2 of the Lysholm type is shown in series with compressor 1. An air inlet8 and associated inlet conduit and manifolds 13 and 14 supply air chargewhich has been compressed to a higher than atmospheric pressure, to acylinder intake conduit 15 which supplies charge-air to two intakevalves, which intake valves 16 a and 16 b operate independently of eachother but open into the same cylinder. Intercoolers 10, 11 and 12 andcontrol valves 3, 4, 5 and 6 are used to help control the air chargedensity, weight, temperature and pressure. The intake valves are timedto control the compression ratio of the engine. The combustion chambersare sized to establish the expansion ratio of the engine.

The engine 100 of FIG. 8, FIG. 9, FIG. 10 and FIG. 11 have cam shafts 21fitted with cams and are arranged to rotate at engine crankshaft speedin order to supply one power stroke for each power piston for eachcrankshaft rotation.

The engine 100 ¹¹ shown in FIG. 11 is characterized by a more extensiveexpansion process, a low compression ratio and capable of producing acombustion charge varying in weight from lighter-than-normal toheavier-than-normal and capable of selectively providing a meaneffective cylinder pressure higher than can the conventional arrangementin normal engines, but having similar or lower maximum cylinderpressure. Engine control module (ECM) 27 and variable valves 3, 4, 5 and6 on conduits, as shown, provide a system for controlling the chargepressure, density, temperature, and mean and peak pressure within thecylinder which allows greater fuel economy, production of greater powerand torque at all RPM, with low polluting emissions for both spark andcompression ignited engines. In alternate embodiments, a variable valvetiming system with the ECM 27 can also control the time of opening andclosing of the intake valves 16 a or 16 b or both, to further provide animproved management of conditions in the combustion chamber to allow fora flatter torque curve, and higher power, with low levels of both fuelconsumption and polluting emissions.

Brief Description of Operation of Engine 100 ¹¹ shown in FIG. 11

The new cycle engine 100  of FIG. 11 is a high efficiency engine thatattains both high power and torque, with low fuel consumption and lowpolluting emissions.

The new cycle is an external compression type combustion cycle. In thiscycle part of the intake air (all of which is compressed in the powercylinders in conventional engines) is compressed by an ancillarycompressor. The temperature rise at the end of compression can besuppressed by use of air coolers, which cools the intake air, and by ashorter compression stroke.

During operation air is supplied to the power cylinder 7 at a pressurewhich has been increased by perhaps from one-third to severalatmospheres, or greater through an air intake conduit 15. Valve 16 bopens by pressure on the top of the valve stem from a very small lobe oncam 21-A for a short period of time near bottom dead center position ofpiston 22 in order to scavenge the cylinder and provide freshcharge-air. Exhaust valves 17, 17′ open for exhaust blowdown slightlybefore intake valve 16 b opens to admit scavenging air. The cylinder 7is efficiently scavenged mostly during the turnaround time of piston 22.During the first part of the compression stroke, perhaps as early as10-20° after bottom dead center of piston 22 position, the first intakevalve 16 b closes, at a later time the exhaust valve 17, 17′ closes, atwhich point compression of the fresh air charge starts, whichestablishes the compression ratio of the engine. At the point theexhaust valves 17, 17′ closes or any point later, the second intakevalve 16 a and perhaps 16 b, by a second lobe 21-C is, preferably,opened to introduce more of the temperature and density adjusted charge,if needed.

An intake valve disabler 31 in FIG. 10 (there are several on the market,for example. Eaton Corp. and Cadillac) can disable intake valve 16 awhen light-load operation does not require a high mean effectivecylinder pressure. Alternatively, the air bypass valve (ABV) 6 is openedwholly or partially to re-circulate some or all of the charge-air backthrough the compressor 2 in order to relieve the compressor ofcompression work during light-load operation. Additionally, air bypassvalve 4 can re-circulate part or all of the air pumped by compressor 1on demand in order to reduce charge pressure and density.

One suggested, preferred method of operation of the new cycle engine 100¹¹ is thus:

-   -   1. Intake air at greater than atmospheric pressure that has been        compressed by at least one compressor and has had its        temperature adjusted by bypass systems and charge-air coolers        are introduced into the cylinder 7 through intake valve 16 b        which is opened by a very small lobe 21-D on cam 21-A at or near        bottom dead center of piston 22 at the end of the power-stroke,        as exhaust valve(s) 17 a, 17 a′ have opened a little earlier        (perhaps 40° before bottom dead center) for exhaust blowdown.        The exhaust valve 17 remains open through bottom dead center for        efficient scavenging of the cylinder 7 by blowdown and loop        scavenging. Intake valve 16 b closes as the fresh high-pressure        charge very quickly scavenges the cylinder 7.    -   2. After the power stroke is complete the exhaust valves 17 are        left open for a period of time after the piston has passed        bottom dead center (with intake valve 16 b now closed) in order        to continue to scavenge the power cylinder with the fresh air        charge and further, in order to establish a low compression        ratio of the engine, the compression ratio being established by        the displaced cylinder volume remaining at the point of the        exhaust valve 17 closure being divided by the volume of the        combustion chamber.    -   3. With the cylinder 7 now filled with fresh air which is near        atmospheric pressure, the compression (2nd) stroke continues        and, at the point the exhaust valve is closed, compression        begins for a small compression ratio. This makes it possible to        lessen the temperature rise during the compression stroke.        Compression continues, fuel is added, if not present, and the        charge is fired at the appropriate point near top dead center        and the power-stroke occurs.    -   4. (a) Alternatively, at any point deemed appropriate at the        time or after the exhaust valve has closed and compression of        the charge has begun, a secondary density and        temperature-adjusted air charge can be injected through intake        valve 16 a and perhaps by a second lobe 21-C on cam 21-A,        through intake valve 16 b. Compression continues with the        secondary air charge injection, fuel is added, if not present,        the charge is ignited and combustion produces a large expansion        of the combusted gases producing great energy. This energy is        turned into high torque and power by the engine.    -   (b) When even greater power is required, the air charge can be        increased in density and weight by being passed through one or        more intercoolers and by increasing compressor speed or by        cutting in a second stage 2 of auxiliary compression, FIG. 11.        Alternatively, the timing of closing exhaust valve 17 and of the        opening of intake valve 16 a could be altered temporarily to        close earlier and to open earlier, respectively, for a larger        charge.    -   5. Near bottom dead center of the piston, exhaust valves 17, 17′        open and the cylinder is scavenged by blowdown and by the air        injected by primary intake valve 16 b.        Detailed Description of the Operation of the Engine 100 ¹¹ of        FIG. 11

Near the end of the power (1st) stroke of the piston 22, perhaps atabout 40° before bottom dead center position of piston 22, the exhaustvalves 17 open for exhaust blowdown, shortly after, high pressure airflows through air conduit 15 from manifold 13 and 14, as shown in FIG.11, through an intake valve 16 b into the cylinder 7, the cylinder 7 isscavenged, intake valve 16 b closes. (Intake valve head 30 can berecessed as shown in FIG. 11 in order to form a pipe-like opening intocylinder 7 so that when the charge-air is highly compressed, and as muchas 500-530 psi is feasible, the small lobe 21-D on cam 21-A of intakevalve 16 b lets in a small blast of the high pressure air which isdirected downward for loop scavenging, during or just after piston 22turnaround at bottom dead center piston position.) Exhaust valves 17remain open during the first part of the compression (2nd) stroke ofpiston 22. The cylinder 7 is now efficiently scavenged by blowdown andby loop scavenging and at any point during the compression stroke, thecylinder 7, now being filled with fresh air, the exhaust valves 17, 17′can close. But since a low compression ratio is desired, the exhaustvalves 17, 17′ can be held open until the piston has reached the pointthat is desired to establish the compression ratio. At, or after thetime exhaust valve 17 closed, a secondary charge of high pressuretemperature adjusted air which has been compressed by compressor 1and/or 2 can be injected by the second intake valve 16 a and, ifdesired, by another lobe 21-C (in phantom) on the first valve 16 b intothe same cylinder. (When high torque and power is needed, the density ofthe charge-air can be greatly increased by increasing the speed of theprimary compressor 1 or by cutting in another stage of compression, asin compressor 2, FIG. 11, and routing the charge through aftercoolers10, 11 and 12. Also the speed of compressor 2 can be increased to shovein more charge on the back end.) Compression would continue, for a smallcompression ratio, fuel would be added, if not present, the charge wouldbe ignited and the gases expanded against piston 22 for the powerstroke.

For light-load operation, a shut-off valve (or a valve disabler 31 shownin FIG. 10 on the intake valve 16-A) could temporarily restrain theintake air, or hold the intake valve 16 a closed. This would add to thefuel economy of the engine. Alternatively, during light-load operationthe shutter valve 5 could be closed and the air bypass valve 6 opened sothat air pumped by compressor 2 would be returned to the inlet conduitof the compressor 2 without any compression taking place. In the samemanner valves 3 and 4 could return part of the air being pumped throughback to the intake 106 of compressor 1.

The ancillary automatic intake valve 26, FIG. 10, which can be of thespring-returned disc type, can be arranged, as shown in FIG. 10, toprevent any back-flow of charge-air into conduit 15 if the cylinderpressure should equal or exceed the pressure in conduit 15 during thecompression stroke of piston 22 before intake valve 16 a had closedcompletely. (As in other engine designs herein presented, the optionalautomatic valve 26 shown in FIG. 10 can be utilized to control thepressure ratio of this engine. If the intake valve 16 a is kept open tonear top dead center, the closure of valve 26 and the pressure ratio ofcylinder 7 would be controlled by control valves 3, 4, 5 and 6 and bycompressor speed and by any throttle valve present.) Automatic valve 26would seal the intake from conduit 15 during the last part of thecompression stroke, ignition of the charge and during the power stroke.

Fuel can be carbureted, injected in a throttle body 56 in FIG. 15through FIG. 17, and 56 in FIGS. 19 and 20, or the fuel can be injectedinto the inlet stream of air, or injected into a pre-combustion chamberor, injected through intake valves 16 a, 16 b, (the latter during itssecond opening by lobe 21-C on cam 21-A), or it may be injected directlyinto the combustion chamber at or past point x in theexhaust-compression stroke. The fuel can also be injected later and inthe case of diesel operation can be injected at the usual point fordiesel oil injection, perhaps into a pre-combustion chamber or directlyinto the combustion chamber or directly onto a glow plug. After thetemperature-and-density-adjusting-air charge has been injected, if used,compression of the charge continues and with fuel present, is ignited atthe opportune time for the expansion stroke. (The compression ratio isestablished by the displaced volume of the cylinder remaining afterpoint x (at exhaust valve closure) has been reached, being divided bythe volume of the combustion chamber. The expansion ratio is determinedby dividing the cylinders total clearance volume by the volume of thecombustion chamber.) Now the fuel-air charge has been ignited and thepower stroke of piston 22 takes place as the combusted gases expand.Near bottom dead center of the power stroke, the exhaust valve(s) 17opens and the cylinder 7 is efficiently scavenged, first by blowdown,then by loop scavenging by air from intake valve 16 b at the end of thepower stroke or shortly after.

It can be seen that the later the point in the compression stroke thatpoint x (the later the exhaust valve is closed) is reached, the lower isthe compression ratio of the engine and the less the charge is heatedduring compression.

It can also be seen that the later the temperature-density-adjustingcharge is introduced, the less work will be required of the engine tocompress the charge, the later part of which has received somecompression already by compressor 1 and/or by an ancillary compressor 2.In some cases where the load is light and fuel economy important theancillary compressor could be bypassed with the secondary air chargeperhaps eliminated temporarily and the total charge weight could be lessthan that of a conventional engine.

Referring now to FIG. 12 there is shown a pressure-volume diagram for ahigh-speed Diesel engine compared to the engines of this invention,showing three stages of intercooled compression and a fourth stage ofuncooled compression indicating a compression ratio of approximately2:1, which arrangement is suggested for optimum power, with efficiencyfor the engine of this invention. (The charts of FIG. 13 and FIG. 14show some of the improvements of the engine of this invention overcurrent heavy-duty 2-stroke and 4-stroke engines.)

There are several features that improve the thermal efficiency of theengine of this invention. Greater power to weight ratios will provide asmaller engine with less frictional losses. The extended expansion ratioresults in higher thermodynamic cycle efficiency, which is shown intheoretical considerations. There are also definite efficiency gains ina “staged” compression process even with external compressors withassociated piping, intercoolers and aftercoolers, etc. There is a verysignificant energy savings when air is compressed in intercooled stages.Less energy is used in compressing a charge to 500 psi in 2, 3 or 4intercooled stages than is used to compress the hot charge to the same500 psi in a conventional engine. A normal engine uses approximately 20%of its own energy produced to compress its own air charge. Calculationsshow a significant energy savings in an engine if the air is compressedin aftercooled stages. Compressing a charge in only two stages to 531psi (a 13:1 compression ratio) reduces the energy used by 15.8% overcompressing to the same 531 psi level in a single stage as does the Ottoand the Diesel Cycle engines. Three stages of intercooled compressionraises the savings to 18%. This is the ideal. Degradation from the idealshould not exceed 25% which leaves a 13.5% energy savings. This 13.5%energy savings times the 20% of a normal engine's power used forcompressing its own charge, is a 2.7% efficiency improvement by thecompression process alone. This is one of the advantages of this enginewhich adds to the other thermal efficiency improvements. The lowcompression ratio, along with the large expansion ratio providesimprovements in efficiency, torque, power and durability while loweringpolluting emissions.

-   -   Note 1—In FIG. 12 the travel distance of the line for engine B        on the horizontal coordinate indicates the theoretical volume at        the greater density. The density is kept at that level at the        actual combustion chamber volume (as shown by dashed line V)        regardless of the density, by pumping in more charge at the        back-side.

Referring now to FIG. 13, there is shown a chart which compares variousoperating parameters of the engine of this invention (B) with theoperation parameters of a popular heavy-duty, 2-stroke diesel cycleengine (A).

The parameters shown for engine A are the normal operating parametersfor that engine, e.g., compression ratio, combustion temperatures,charge density, etc. The parameters chosen to illustrate for engine (B)are given at two different lower “normal” compression ratios withcorresponding “effective” compression ratios, intercooled and uncooled,for two different levels of power output. The columns showing chargedensities and expansion ratios indicate the improvements in steady statepower density improvements for engine B even at a substantially lowernominal compression ratio and an effective compression ratio as low as2:1 as shown in FIG. 10. The columns showing low temperatures at the endof combustion, and the column showing extended expansion ratios indicatemuch lower polluting emissions. Indicated power improvements of engine(B) over engine (A) even at the lower nominal compression ratio are noless than 50%.

Referring now to FIG. 14 there is shown a chart which compares thevarious operating parameters of the engine of this invention (B) withthe operating parameters of a popular heavy-duty 4-stroke diesel engine(A).

When comparisons similar to those of FIG. 13 are made, steady statepower and density improvements are much higher since engine (B) firesthe denser charge twice as often as engine A for an indicatedsteady-state power density improvement of 180% over engine (A).

Referring now to FIG. 15, there is shown a schematic drawing of anengine representing the engines of FIGS. 5-7, and FIGS. 9-10 with aseparate air cooler 10 for ancillary compressor 2, with the primarycompressor 1 supplying two manifolds 13 and 14 and having separate aircoolers 11 and 12 and charge-air conduits 114 and 115, and having eachmanifold having three cylinder air intake runners 15 a-15 c, 15 d-15 f,respectively. The engine of FIG. 15 operates the same as the engines ofFIGS. 5-7 and FIGS. 9-10 and here shows suggested valving positions forshutter valve and air bypass valves for supplying the manifolds 13 and14 with an air charge optimum for light-load operation of the engine ofFIGS. 5-7 and FIGS. 9-10. For light-load operation, the shutter valve 5can be closed and the air bypass valve 6 of compressor 2 (if compressor2 is not supplying primary air charge directly to conduit 32 and intakevalve 15-B) can be opened fully or partially so that part or all of theintake air of compressor 2 can be returned to the intake of compressor 2with little or no compression occurring there. Also, the shutter valve 3of compressor 1 can be closed, passing the air charge away from thecoolers 11 and 12, the air bypass valve 4 would be closed to preventre-circulation of the now compressed and heated air back throughcompressor 1 and whose shutter valve 3 and air bypass valves are bothdirecting the air charge uncooled into manifold 13 and 14 for a lowdensity heated charge for light-load operation. Preferably compressor 2would be kept operative in order to supply the primary air chargethrough conduits 110, 32 and intake valve 16-B for a more economicalscavenging-charging system.

Referring now to FIG. 16, there is shown suggested valve positions forsupplying manifolds 13 and 14 with an air charge optimum for medium-loadoperation for engines of FIG. 16 or for the engines of FIGS. 5-7 andFIGS. 9-10. For medium-load operation the shutter valve 5 of compressor2 is closed and the air bypass valve 6 would be opened to pass the aircharge uncooled and without compression to the intake of compressor 1where closed shutter valve 3 and closed air bypass valve 4 directs theair charge now compressed by compressor 1 past the intercoolers tomanifolds 13 and 14 with the air compressed and heated by compressor 1,for medium-load operation.

Referring now to FIG. 17, there is shown a suggested scenario forproviding the engine of FIG. 17 or for the engines of FIGS. 5-7 andFIGS. 9-10 with a high density air charge for heavy duty, high poweroutput operation. FIG. 17 shows both shutter valves 3 and 5 open andboth air bypass valves 4 and 6 closed completely so that the primarystage of compression is operative and a second stage of compression hasbeen made operative for maximum compression of the charge and the entireair charge is being passed through the intercoolers 10, 11 and 12 toproduce a cooled, very high density air charge to manifolds 13 and 14and to the engines power cylinders for heavy-load operation. Thisproduces a very high mean effective cylinder pressure for high torqueand power with maximum cylinder pressure being the same as, or lowerthan that of normal engines.

Referring now to FIG. 18, there is shown a schematic drawing of analternative type of auxiliary compressor 2′ for the engines of FIGS. 5-7and FIGS. 9-10 and for any other engine of this invention and a systemof providing a system for cutting out the auxiliary compressor when highcharge pressure and density is not needed. For relieving compressor 2′of work, (if the air compressed by compressor 2 does not go directly toconduit 32 and valve 16-B to supply the primary air charge) shuttervalve 5 is closed and air bypass valve 6 is opened so that air pumpedthrough compressor 2′ can re-circulate through compressor 2, thusrelieving the compressor of compression work.

Referring now to FIG. 19, there is shown a schematic drawing of theengines of FIGS. 5-7 and FIGS. 9-10, illustrating means of controllingcharge-air density, temperature and pressure by varying directions ofair flow through various electronic or vacuum operated valves and theirconduits.

FIG. 19 also shows the various charge-air paths possible by using hollowarrows to indicate heated air paths and solid arrows to indicate themore dense intercooled air paths thereby indicating how charge-airtemperatures can be thermastatically or electronically controlled bydividing the air charge into two different paths. Alternatively, all ofthe air charge can be directed past the air coolers or all can bedirected through the air coolers, as shown in FIG. 19. Also, FIG. 19shows how the pressure output of compressor 1 and compressor 2 can bevaried by partially or fully opening air bypass valves 4 and 6 or bycompletely closing one or both of these control valves. An enginecontrol module (ECM) 27 is suggested for controlling the variousoperating parameters of the engines of this invention.

Referring now to FIG. 20, there is shown is a schematic drawingdepicting an alternate arrangement in which an electric motor 34preferably drives the compressor(s) of any of the engines of the presentinvention.

Charge-Air Cooler Bypass (ACB) “Shutter Valve” Control

In this section are described aspects of preferred control componentswhich find application in connection with any of the engines (4-strokeand 2-stroke) of the present invention.

Outline: Valves 3 and 5 are charge-air-cooler bypass solenoid (ACB)valves. In charge-air cooler bypass control, the intake air is switchedbetween two routes by valves 3 and 5, independently of each other:either (a) valve 5 directs the flow from compressor 2 directly to theintake conduit of compressor 1 or (b) through the charge-air cooler 10before flowing to the intake conduit of compressor 1. Valve 3 directsthe flow from compressor 1 either (a) to the conduit 111/121/122 leadingdirectly to the intake manifolds 13 and 14 or (b) it passes the aircharge through charge-air coolers 11 and 12 before it flows to manifolds13 and 14.

An engine control module (ECM) 27 can control the air cooler bypassvalves 3 and 5. The bypass valves may be a shutter type valve to passall or none of the air charge in either direction or valves 3 and 5 maybe of a helical solenoid or other type of valve which can pass part ofthe air charge through bypass conduits 121 and 122 and part through aircoolers 10, 11 and 12 for fine control of the temperature and density ofthe air charge. The ECM could receive signals from sensors such as anengine coolant sensor, a crankshaft position sensor, throttle positionsensor, camshaft position sensor, a manifold absolute pressure sensorand a heated oxygen sensor.

Air By Pass Valve (ABV) Control

Outline: To provide optimum air charging pressure for differing engineoperations conditions, the ECM 27 can send signals to control air bypassvalves 4 and 6. These valves could be on-off solenoid valves, possiblyvacuum operated, or they could be helical solenoids or other type ofvalve which could open part way or all way in order to recirculate partor all of the air charge back through the inlets 10 and 8 of compressors1 and 2 in order to reduce or eliminate entirely the pumping pressure ofeither compressor 1 or compressor 2, or both. Similar arrangements ofair pressure control could be used for additional stages of aircompression if additional stages are used.

The operation could be thus: The ABV valves 4 and 6 can be controlled bysignals from the ECM 27 to control the opening angle of valves 4 and 6to provide the optimum air charging pressures for various engine loadsand duty cycles. When ABV 6 is opened partially some of the air pumpedthrough compressor 2 is passed back into the intake 8 of compressor 2 toreduce compression pressure. When ABV 6 is opened fully all of thecharge of compressor 2 is passed back through compressor 2, thuscompressor 2 only pumps the charge through with no pressure increase.The system can work the same for valve 4 which could bypass some of theair charge pumped by compressor 1 back into the intake conduit 110 ofcompressor 1 in order to reduce air charge density.

With this arrangement, combined with the arrangement of ECM 27 controlof charge-air cooler bypass system for variable valves 3 and 5, thetemperature, density pressure and turbulence of the charge-air can bemanaged to produce the desired power and torque levels and emissionscharacteristics in the power cylinder of the engine.

Engine conditions that could be monitored by ECM 27 in order to effectproper engine conditions in regard to control of ABV valves 4 and 6could include a throttle position sensor (or fuel injection activitysensor), intake air temperature sensor at various points, manifoldabsolute pressure sensor, camshaft position sensor, crankshaft positionsensor, exhaust temperature sensor, a heated oxygen sensor and/or othersensory inputs known to be used in internal combustion engines.

The ECM 27 can control both the shutter valves 3 and 5 and the airbypass valves 4 and 6 in order to maintain the optimum air chargingdensity pressure and temperature at all engine operating duty cycles.

Alternate Combustion Systems

Referring now to FIG. 21, there is shown a schematic transverse view ofa pre-combustion chamber 38′, a combustion chamber 38, a piston crown 22and associated fuel inlet 36, a sparking plug 37, an air or air/fuelmixture inlet 8′ duct, intake valve 16, an exhaust duct 18′ an exhaustvalve 17 suggested for liquid or gaseous fuel operation for the enginesof this invention or for any other internal combustion engine.

There are many choices of systems for compression or spark ignitioncombustion for the engine of this invention, as shown in FIG. 1 throughFIG. 33. Every fuel from avgas to heavy diesel fuels, including thealcohols and gaseous fuels can be spark ignited (SI) in this engine. Onegood SI system would be similar to the system shown in FIG. 21 forcompressed natural gas, propane, hydrogen, gasoline, alcohols or dieselfuel. In this system, an extremely fuel rich mixture constituting theentire fuel charge is, preferably, injected into the pre-combustionchamber 38′. The fuel could be injected through fuel duct 36 with orwithout air blast injection, the air charge, some of which can accompanythe fuel charge would be compressed into the pre-combustion chamber 38′by piston 22 during the compression stroke. Additional air with orwithout additional fuel, could be introduced into the cylinder propereither on the intake stroke or on the compression stroke through intakeconduit 8′. In either case the second combustion stage in the cylinderproper would be with a lean mixture.

The Two-Stage Combustion System Shown in FIG. 21 will Operate in thisManner:

1. Pre-Combustion (First Stage)

Pre-combustion occurs in the pre-combustion chamber 38′ when fuel in anamount much in excess of the amount of oxygen present is injected andignited (injector not shown). This oxygen deficiency along with thecooler, turbulent charge and lower peak temperatures and pressuresgreatly reduces the formation of oxides of nitrogen. The combination ofthe hot pre-combustion chamber wall and intense turbulence promotes morecomplete combustion.

2. Post-Combustion (Second Stage)

Post-combustion takes place at lower pressure and relatively lowtemperature conditions in the space above the piston in the cylinder asthe gases expand from the first stage pre-combustion chamber into thecylinder proper. If there is additional fuel in the cylinder proper, theleaner mixture is ignited by this plasma-like blast from thepre-combustion chamber. The low temperature and the admixture of burnedgases prevent any further formation of oxides of nitrogen. Excess air, astrong swirling action, and the extended expansion process assure morecomplete combustion of carbon monoxide, hydrocarbons, and carbon.

The results of the engine of this invention using the pre-combustionchamber 38 ′ of FIG. 21 are: higher thermal efficiencies due to thegreater expansion, along with a cooler exhaust and a lower level ofpolluting emissions including oxides of nitrogen, and in addition fordiesel fuels, lower aromatics and particulates.

Referring now to FIG. 22 there is shown a schematic transverse sectionalview of an optional cylinder of the engine of this invention which willconvert the 2-stroke engine of FIG. 8 through 33 to a one-stroke cycleengine and will convert the 4-stroke engines of FIG. 1 through FIG. 7and FIG. 33 to operate in a 2-stroke cycle.

By building any 2-stroke engine with all power cylinders double acting,the power to weight ratio can be doubled over the basic engine. One endof the cylinder fires and the other end is scavenged on each stroke fora nominal one stroke cycle engine in the engines of FIG. 8 through FIG.33. Use of double-acting power cylinders in the 4-stroke engine of FIG.1 through FIG. 7 and FIG. 33 converts the engine to a 2-stroke enginebecause one end of the cylinder is scavenged and one end is fired duringeach crankshaft rotation.

In the design of FIG. 22 needed variation of beam 39 length isaccomplished by the beam end forming a scotch yoke 40 and fitting overthe wrist pin 41 of the piston.

The double ended piston 22″ can be linked to the end of a vertical beam39 that pivots at the lower end 42. A connecting rod 19′ is joinedbetween the midpoint of the beam and the crankshaft 20′.

Since the crankshaft 20′ itself does no more than transmit torque, itsmain bearings will be very lightly loaded. As a result little noise willreach the supporting casing. Because of the lever action, the crank (notshown) has half the throw of the piston stroke and can be a stubby,cam-like unit with large, closely spaced pins having substantial overlapfor strength.

The compression ratio can be changed by slightly lengthening orshortening the effective length of the beam 39. This can be done by thelower pivot plate 42 being attached to a block 43 mounted slidably in afixed block 44 and in which block 43 can be moved slidably by a servomotor 45. The gear 45 a rotated by servo motor 45 is much longer thanthe gear 44 a on the screw 43 b which is rotatably attached to block 43and rotates against threads in block 44, causing gear 44 a to slide backand forth on gear 45 a as block 43 reciprocates in block 44. Thus as adiesel, it could be started at 20:1 ratio and then shifted to a 13:1ratio for less friction and stress on parts. This could also beimportant to allow use of alternate fuels.

Referring now to FIG. 23: These same advantages hold true for thealternate design (FIG. 23) in which the pivot 47′ is between theconnecting rod 19 and the piston 22″

The needed variation of the length of the beam 39 (shown in phantom)connecting the piston 22″ to the connecting rod 19 can be accomplishedby forming a scotch yoke 40 on the beam end fitting over the wrist-pin41 of the piston 22″, or by placing a double pivoting link 42′ betweenthe pivot 47′ on the fulcrum of beam 39′ with the pivot 42″ beingattached to a non-movable part 46 of the engine and the terminal end ofbeam 39′ being connected to connecting rod 19 by a pin 47.

Alternately and preferably, for heavy duty engines (marine propulsion,power production, etc.) the power take off of piston 22″ could be with aconventional piston rod 39′ being arranged between piston 22″ and acrosshead 20′ with a connecting rod 19′ between the crosshead 20′ andthe crankshaft (not shown).

Double-acting power cylinders when used in the engine of this inventionwill be especially of importance where great power is desired andcooling water is readily available, e.g., for marine use or for powergeneration.

These double-ended, double-acting cylinders can be used in all of thedesigns of this invention.

Referring now to FIG. 24: There is shown a schematic transversesectional view of a crankshaft, two connecting rods 19′ and 19″ and abeam 39 showing a means of providing extra burn time of a conventional2-stroke or 4-stroke engine.

This layout for any engine provides for double the piston 22′ turnaroundtime of a normal engine during the critical burn period. This is becausepiston 22′ top dead center (TDC) occurs at bottom dead center (BDC) ofthe crank 48. At this point, crankpin motion around piston 22′ top deadcenter is subtracted from the straightening movement of the connectingrod 19′, instead of being added to it as in conventional engines.Reversing the usual action slows piston travel around this point,resulting in more complete combustion and further reducing emissions.

The extra burn time provided by the design of FIG. 24 can be importantin the engines of this invention and to any Otto or Diesel cycle engine.

Operation of the engine constructed and arranged with the additionalburning time would be the same as the other engines of this inventionproviding high charge density, low compression-ratios with a meaneffective pressure higher than conventional engines but with morecombustion time than other engines while producing even less pollutingemissions.

Since the crankshaft 48 in FIG. 24 itself does no more than transmittorque, its main bearings will be very lightly loaded. As a resultlittle noise will reach the supporting casing. Because of the leveraction, the crank can have as little as half the throw of the pistonstroke (depending on the point of the fulcrum), and can be a stubby,cam-like unit with large, closely spaced pins having substantial overlapfor strength.

This layout also provides for nearly twice the combustion time of aconventional engine during the critical burn period. This is becausepiston top dead center occurs at bottom dead center (BDC) of the crank.

The Engine 100 ²⁵ of FIG. 25

Referring now to FIG. 25 of the drawings, there is shown a six cylinderreciprocating internal combustion engine in which all of the cylinders 7a-7 f (only one (7 f) of which is shown in a sectional view) andassociated pistons 22 a-22 f are adapted to operate in a 2-stroke cycleand all cylinders are used for producing power to a common crankshaft 20via connecting rods 19 a-19 f, respectively. A compressor 2 supplies airto scavenging ports 52 by way of optional shut-off valve 33-M andconduit 32 and to cylinder charge inlet valve(s) 16 and 16′ by way ofconduits 15. The engine of FIG. 25 is adapted to operate in a 2-strokecycle so as to produce six power strokes per revolution of thecrankshaft 20. To this end, compressor 1 takes in an air charge whichmay have been previously subjected to compressing to a higher pressure,via an admission control valves 5 and 6 through an intake conduit 110,leading from compressor 2 by way of intercooler 10 or bypass conduit 104and shutter valve 5. During operation of the engine of FIG. 25,compressor 2 receives atmospheric air through inlet opening 8,pre-compresses the air charge into conduit 101 leading to controlshutter valve 5 which in response to signals from the ECM 27, to shuttervalve 5 and air bypass valve 6, will direct the compressed chargethrough intercooler 10 or through cooler bypass conduits 104 tocompressor 1. The air charge is compressed within compressor 1 by itsassociated piston 131, and the compressed air charge is forced throughan outlet into a high pressure transfer conduit 109 which leads tocontrol shutter valve 3 which, if open, directs the air throughintercooler 11 and 12 to manifolds 13 and 14 or, if closed, through aconduit and air bypass valve 4 which can direct part of the air chargeback through inlet conduit 104 of the compressor 1, or valve 4 if fullyclosed, directs all of the charge from compressor 1, in response tosignals from the engine control module (ECM) 27, through theintercoolers 11 and 12 or through the bypass conduit 111/121/122 intomanifolds 13 and 14. Manifolds 13 and 14 are constructed and arranged todistribute the compressed air charge by means of branch conduits 15 a-15f to inlet valves 16 and 16′ of the cylinder 7 a, and to the remainingfive power cylinders 7 b-7 f. In an alternate embodiment, instead ofproviding scavenging air through conduit 32′, scavending air is providedthrough shut-off valve 49 and conduit 50 and pressure reducing valve 25to air box 51, through conduits 125 a-125 f to scavenging ports 52 a-52f.

The engine 100 ²⁵ shown in FIG. 25 has a camshaft which is arranged tobe driven at the same speed as the crankshaft in order to supply oneworking stroke per revolution for the power pistons. The compressor canbe reciprocating, comprised of one or more stages of compression withone or more double-acting cylinders, one is shown, 1 in FIG. 25. Thecompressor can be driven by associated connecting rods 19 g tocrankshaft 20 which can have throws of different lengths for differentlength piston strokes for the air compressor(s) than those of the powerpistons. In addition, compressor 1 can be driven by a second crankshaft(not shown) which is driven by a gear meshing with a step-up gearmounted on the common crankshaft. The ancillary rotary compressor, aLysholm type is shown 2, can be driven by a V-pulley being rotated by aribbed V-belt and has a step-up gear arranged between the V-pulley andthe compressor drive shaft. The rotary compressor 2 could also have avariable speed, or two speed drive, as in some aircraft engines.

The operation of engine 100 ²⁵ shown in FIG. 25 is thus: Charge-air isinducted into the inlet opening 8 of compressor 2. From there it ispumped through the compressor 2 where it is directed by shutter valve 5through the intercooler 10 or through a conduit to air bypass valve 6where it is directed to the 25 inlet of compressor 1. The charge is thenpumped by compressor 1 through the outlet valve to shutter valve 3 whichdirects the air charge either through intercoolers 11 and 12, tomanifolds 13 and 14 or into a conduit leading to air bypass valve 4which can direct a part of the charge back through the inlet ofcompressor 1 or valve 4 directs the charge wholly or partially to theshutter valve 3 which directs the charge wholly or partially throughintercoolers 13 and 14, or directly to manifolds 13 and 14 whichdistributes the temperature-adjusted charge-air to cylinder 7 inletvalves 16 and 16′ to each power cylinder of the engine. An off-and-oncontrol Valve (not shown) and conduit 32′ directs air to air box 51 andto scavenging ports 52 a-52 f in the bottom of cylinders 7 a-7 f. In thealternates embodiment (shown in phantom in FIG. 25), the scavenging airis directed through pressure reduction valve 25, arranged on conduit 50to provide and adjust scavenging air pressure from compression 1.Another option to reducing the manifold air pressure for scavenging thecylinders 7 a-7 f is to use the manifold air through conduit 50, air box51 and intake ports 52 a-52 f without reducing the pressure frommanifolds 13 and 14. The air would be used at full pressure forscavenging by the scavenging ports 52 a-52 f in FIG. 25 and throughinlet port 52″ and exhaust port 52′ in FIG. 30, which ports 52 a-52 f,52′ and 52″ would be constructed much smaller than normally done. Inthis instance, although the scavenging ports were smaller-than-normal,the higher-than-normal pressure scavenging air would be very efficient.Several means of scavenging the cylinders are suggested herein. FIG. 26illustrates more clearly (although in phantom) the preferred system ofsupplying low pressure scavenging air. Conduit 32′ and valve 33 (shownin phantom in FIG. 26) channels air from conduit 110 from compressor 2to conduit 50 which supplies scavenging air to air box 51.

The engine control module (ECM) 27 (see, for example, FIG. 26) controlsvalves 3, 4, 5, and 6 in order to adjust the pressure, temperature anddensity of the charge going to the combustion chambers and valve 25, andcan selectively direct a portion, a portion at a reduced pressure of theair charge to scavenging ports 52 and can control valve 53 and valves49′ to open or close to select the mode of scavenging desired. The ECMcan also control a variable-valve-happening control system to adjust thevalve opening time and duration of opening time of inlet valves 16 andexhaust valves 17 in relationship to the degree or angle of rotation ofcrankshaft 20, in order to adjust the compression ratio of the enginefor optimum performance in regard to power, torque, fuel economy, fuelcharacteristics and to scavenging mode desired.

The Preferred Operation of the Power Cylinders Shown in FIG. 25 is inthis Manner:

After blowdown and scavenging of the cylinder 7 has taken place thecylinder is now filled with fresh air, and piston 22 has closed exhaustports 52 and the piston 22 is in its scavenging-charging stroke and isrising with the exhaust valve 17 still open, at any point, perhaps asearly as 120 to 90 degrees before top dead center, the exhaust valve 17is closed to establish the compression ratio and begin compression,intake valve 16, 16′ are opened at that time or later in order toproduce the desired charge density and weight desired, the compressedair charge or fuel air mixture is injected through intake valve 16, 16′,intake valve 16, 16′ is then closed. Compression of the charge whichstarted at point X, the point where exhaust valve 17 was closed,continues with the compression ratio being established by the cylinderclearance volume remaining at point x, divided by the combustion chambervolume. Fuel can be injected into the secondary compressed air streambeing injected into the combustion chamber or injected into apre-combustion chamber (one is shown in FIG. 21) or may be injecteddirectly into the combustion chamber. After the closure of intake valve16, 16′, the fuel or more fuel can be injected into the midst of thecharge swirl for a stratified charge combustion process, or as incompression ignited engines fuel can be injected directly into thecombustion chamber, perhaps directly onto a glow plug, if suggestedpre-combustion chamber is used or not, and can be injected continuouslyduring part of the expansion stroke for a mostly constant pressurecombustion process.

The fuel-air mixture is ignited by spark plug, by compression ignition,or by low plug at the point deemed most efficient, preferably before topdead center of the compression stroke of piston 22. The expansion strokeof piston 22 takes place as the expanding gases force the piston towardbottom dead center. Near the end of the power stroke, perhaps about 40°before bottom dead center, scavenging ports 52 are uncovered, near thesame time exhaust valve(s) 17 in the engine head are opened and a rapidblowdown and scavenging takes place in any of four ways as shown in FIG.27, FIG. 28, FIG. 29 and FIG. 30. In any case the exhaust valves 17, 17′remain open past bottom dead center and for a significant part of thescavenging-charge-adjusting stroke in order to establish the enginescompression ratio.

Referring now to FIG. 26, there is shown a schematic drawing showing anengine similar in structure and operation to the engine 100 ²⁵ of FIG.25, having two compressors, but differing in that compressor 1 isdepicted as a Lysholm rotary compressor, and compressor 2 is depicted asa turbo compressor, and having one air cooler for the secondarycompressor, two air coolers for the primary compressor, dual manifolds,with shutter controls, air bypass controls and conduits for differentair paths. Also shown is an engine control module (ECM) 27 which cancontrol charge and scavenging air pressures, density and temperatures inorder to effect the desired output and emissions characteristics of theengine. Alternate sources of scavenging air are shown, the preferred onebeing from conduit 110 by way of conduit 32′. Air paths are shown byarrows, hollow arrows for uncooled compressed air and solid arrows forcooled denser air. Also shown are air bypass valves (in this case bothclosed) which, with the shutter valves (one of which is closed and oneof which is partly open, the latter to allow cooling of part of thecharge), can control the charge temperature, weight and density asrequired for best engine performance.

Referring now to FIG. 27, there is shown one system of efficientscavenging of the exhausted products of the engine of FIG. 25;

Scavenging System A (FIG. 27)

Blowdown of exhaust occurs at from about 40° before bottom dead centerto perhaps 40-50° after bottom dead center, with exhaust valves 17opening at approximately the sane time the ports 52 are opened andremaining open after bottom ports are closed by piston 22, and closinglater causing a low compression ratio.

Scavenging air can be supplied from a manifold with perhaps apressure-reducing valve 25 on conduit 50 or, preferably scavenging aircan be supplied from conduit 32′ from ancillary compressor 2, (shown inphantom). In this case, bottom ports 52 open shortly before exhaustvalves 17 open. Blowdown occurs through bottom ports 52 out throughbottom exhaust conduit and valve 53 to main exhaust pipe 18, at sametime or shortly after, exhaust valves 17 open and blowdown of theexhaust occurs both at the top of the cylinder through exhaust valves 53and 17, and through exhaust manifold 18′ and pipe 18 to the atmosphere.The exhaust valve 17 then stays open through a significant part of the2nd or exhaust-charge stroke for additional scavenging, this part bypositive displacement. During this scavenging-charging stroke theexhaust valve 17 may be closed at any point after the first 20 percentof piston 22 travel. Now at any point with cylinder 7 being now filledwith fresh air, exhaust valve 17 can close and intake valve 16′ open toadmit pressurized air which has its temperature adjusted to what isdeemed proper. The later in the exhaust-charging stroke the exhaustvalve 17 is closed, the lower is the compression ratio of the engineestablished. If closed early enough the effective compression ratio canbe as much as 13 or 16 to 1, if closed later the effective compressionratio can be as low as 2:1. At any point after exhaust valve 17 hasclosed, and the compression ratio has been established, and beforepiston 22 has reached top dead center, the air charge, with temperaturedensity and pressure adjusted may be introduced by opening and thenclosing intake valve 16. All of the operating parameters suggested woulddepend on the duty cycle of the engines, e.g., power requirements,efficiency, emissions considerations and the fuel used.

An engine control module (ECM) 27 is shown with connections to thecritical control valves of the engine which can be adjusted accordingthe conditions signaled to the ECM 27 from various sensors in theengine.

Referring now to FIG. 28, there is shown a second system of efficientlyscavenging the engine of FIG. 25;

Scavenging System B (FIG. 28)

Exhaust blowdown occurs through exhaust valves 17 only, with scavengingair being supplied by compressor 2 by way of conduit 32′, oralternatively from manifolds 13 and 14 through conduits 50 past controlvalve 49 and optional pressure control 25 into air box 51 and throughscavenging ports 52 in the bottom of the cylinders 7, up through thecylinder 7, out exhaust valves 17 and through exhaust pipe 18, withvalve 53 being closed. In this system as piston 22 approaches bottomdead center in the power expansion stroke, ports 52 would be uncoveredby piston 22 and as blowdown occurs pressurized air would be injectedthrough all bottom ports 52 and would sweep combusted products throughexhaust valves 17 which open perhaps before ports 52 for the exhaustblowdown. The bottom ports can be constructed to open at perhaps 40°before bottom dead center and could close at the same point after pistonbegins its second stroke. The exhaust valves 17 could remain open afterbottom ports 52 are closed to aid in scavenging by positive displacementby piston 22 and to establish the desired compression ratio which isestablished by the point at which exhaust valves 17 close.

During this scavenging-charging stroke of piston 22 the cylinder 7 beingnow filled with fresh air, the exhaust valve 17 may be closed at anypoint after the first 20 percent or so of piston 22 travel. Now at anypoint exhaust valve 17 can close and intake valve 16 can open to admithighly pressurized air which has its temperature and density adjusted towhat is deemed proper. The later in the exhaust-charging stroke theexhaust valve 17 is closed, the lower is the effective compression ratioof the engine established. If closed early enough the effectivecompression ratio can be as much as 13 or 19 to 1, if closed later theeffective compression ratio can be as low as 2:1. All of the operatingparameters suggested would depend on the duty cycle of the engines,e.g., power requirements, efficiency and emissions considerations andthe fuel used.

An engine control module 27 is suggested for use as shown forcontrolling the various operating conditions desired and as signaledfrom the engine's various sensors.

Referring now to FIG. 29, there is shown a third efficient system ofscavenging the engine of FIG. 25;

Scavenging System C (FIG. 29)

This scavenging system would be that shut off valves 49′ would beclosed, (or valves 25 and 49 could be eliminated), with bottom portsopened to the atmosphere by valve 53, one inlet valve 16 leading frommanifolds 13 and 14 to cylinder 7 could be opened for a very shortperiod of time by a cam, perhaps by a small lobe on a cam that has alarge lobe to open the same valve (as 21-C in FIG. 11) at a differentcrank angle, at the same time ports 52 were uncovered by piston 22 andexhaust valves 17 were opened. The high pressure air would quickly sweepcombusted gases through ports 52 and exhaust valves 17, through theirrespective exhaust pipes 17 and 17′ to the atmosphere. The intake valve16 would close quickly, no later than the time exhaust ports 52 closed.The exhaust valve would remain open for further scavenging and for thereduction of the compression ratio of the engine. Alternatively bottomexhaust valves 53 would be closed and as bottom ports 52 were uncoveredby piston 22, exhaust valves 17 would also open earlier for blowdown,air from the airbox 51 supplied by conduit 32 would blow into ports 52and scavenge the cylinder 7 through exhaust valves 17.

During this scavenging-charging stroke the exhaust valve 17 is closed ata point after the first 20 percent or so of piston 22 travel. At anypoint after exhaust valve 17 has closed, the cylinder 7 being now filledwith fresh air, and the compression ratio having been established, andbefore piston 22 has reached top dead center, additional (secondary) aircharge, with temperature density and pressure adjusted is introducedwhen needed by opening a second intake valve 16 and or by another lobe21-C on the same cam (see 21-C, FIG. 11) opening the same intake valveagain. All of the operating parameters suggested would depend on theduty cycle of the engines, e.g, power requirements, efficiency andemissions considerations and the fuel used. The later in theexhaust-charging stroke the exhaust valve 17 is closed, the lower is thecompression ratio of the engine established. If closed early enough theeffective compression ratio can be as much as 13:1 or 22:1, if closedlater the effective compression ratio can be as low as 2:1.

An engine control module could control all of the conditions required ofthe engine.

Referring now to FIG. 30, there is shown a fourth system of efficientscavenging the engine of FIG. 25.

Scavenging System D (FIG. 30)

In this system exhaust blowdown occurs through the top exhaust valves 17and through part of the bottom scavenging ports 52′ which open justbefore bottom dead center, perhaps 40°, and simultaneously with or justafter the top exhaust valves open. At the time bottom ports 52′ areopened, or shortly after, exhaust valves 17 are also opened, or, valve53 leading to bottom exhaust line 18 is already open, and exhaustblowdown occurs over the next, 40° or so after bottom dead center, withscavenging air being injected through at least one of the bottom ports52″ which has been constructed to receive pressurized air from air box55 supplied by conduit 32′ or 50 at such a time the ports 52′ are openedby piston 22 and the pressure in cylinder 7 has dropped below thepressure in air-box 55. After ports 52′ are closed, exhaust valvesremain open through a significant part of the second or exhaust-chargestroke of piston 22 for additional scavenging by positive displacementand in order to establish a low compression ratio.

During this scavenging-charging stroke the cylinder 7 being now filledwith fresh air, exhaust valve 17 may be closed at any point after thefirst 20 percent or so of piston 22 travel. Now at any point exhaustvalve 17 can close to establish the compression ratio and inlet valve 16can open to admit a secondary pressurized air charge which has itstemperature and pressure adjusted to what is deemed proper. The later inthe exhaust-charging stroke the exhaust valve 17 is closed, the lower isthe compression ratio of the engine established. If closed early enoughthe effective compression ratio can be as much as 13:1 or 22:1, ifclosed later the effective compression ratio can be as low as 2:1. Allof the operating parameters suggested would depend on the duty cycle ofthe engines, e.g., power requirements, efficiency and emissionsconsiderations and the type of fuel used, and can be controlled by anengine control module which receives signals relating conditions incertain engine areas and which are relayed to the ECM 27.

Referring to FIG. 31, there is shown a schematic drawing depicting analternate arrangement in which an electric motor 34 preferably drivesthe air compressors of an engine similar to that of FIG. 25.

Referring now to FIG. 32, there is shown a schematic drawing showing the2-stroke engine of FIG. 25 and FIG. 26 and having only one compressor 1for supplying both scavenging and charge-air. Also shown are a shuttervalve 3 and an air bypass valve 4, valves 16 and 17 controlling chargeand scavenging air and valves 53 and 53′ for releasing exhaust blowdownout of the cylinder bottom ports 52 through exhaust conduit 18 to theatmosphere. Thus the engine of FIG. 32 can perform all of the featsdescribed for the engine of FIG. 25 and described for the engine of FIG.25, FIG. 26, FIG. 27, FIG. 28, FIG. 29, FIG. 30 and FIG. 32. Also shownis an engine control module (ECM) 27, and connections to various valvesin order to manage the charge and scavenging air temperature, density,weight and pressure, and the pressure and path of the scavenging air toachieve the desired results from the engine. Arrows show the pathspossible for the heated (hollow arrows) air and the cooled (solidarrows), air, and for the charge-air to pass through the air bypassvalve 4, all in order to adjust air pressure, density, weight andtemperature for optimum engine performance.

The Engine 100 ³³ System of FIG. 33

Referring now to FIG. 33, there is illustrated a six cylinder internalcombustion engine in which part of the cylinders 62 through 65 are usedfor producing power and two of the cylinders, cylinders 66 and 67, areused for compressing the air necessary to operate the engine. Asupercharger 57, in this case preferably a Lysholm type, is used toboost the atmospheric pressure air received through air intake 8′,before the air enters compressor cylinders 66 and 67. A shutter valve 3′and air bypass valve 4′ re-circulate the charge-air back throughcompressor 57 when both are open, to lessen compressor work and reducecharge densities for light-load operation. When air bypass valve 4′ isclosed shutter valve 3′ can open or close to send the air charge to thecylinders cooled or uncooled, respectively, in order to managecombustion temperatures and temperatures for optimum performance.

The second stage of compression is transferred from compressioncylinders 66 and 67 through conduits 201, 202 to shutter valve 4″ which,when closed, sends the compressed charge through conduit 204 andintercooler 11 and conduit 205 to the engine manifold 58′ in a cooledcondition. If opened, shutter valve 4″ directs the charge away fromcooler 11 through conduit 203 and 205 to the power cylinders withoutcooling.

By having its camshaft arranged to rotate at one-half crankshaft speed,the engine 100 ³³ operates in a 4-stroke cycle, with a low compressionratio, an extended expansion ratio and high mean effective cylinderpressure when operated in a manner just as described herein for theengine of FIG. 3.

Alternatively, the engine of FIG. 33, with one or more of its cylindersacting as compressor cylinders and having its camshaft arranged torotate at crankshaft speed, operates in a 2-stroke cycle with the lowcompression ratio, high mean effective cylinder pressure and an extendedexpansion ratio when operated in the manner described herein for theengines of FIG. 8, FIG. 9 and FIG. 11.

Still referring to FIG. 33 of the drawings, additional fuel savings canbe achieved in any of the engines of the present invention describedhereinbefore by use of an economizer constructed as an air compressorretarder brake. For discussion of the disclosed retarder brake, thissix-cylinder engine 100 ³³ represents any of the engines of thisinvention which use externally compressed air (FIG. 1 through FIG. 33)to either fully supply charge-air or which use it to enhance engineperformance. The air retarder brake illustrated has a compressor 57Aoperatively connected to the drive shaft of the vehicle (not shown) orgeared to the engines crankshaft 20 and stores energy produced duringbraking or downhill travel which is utilized to supply compressed air tothe engine power cylinders via the transfer manifold 58. Such aneconomizer is coupled with an air reservoir 59 and during the time inwhich the economizer reservoir air pressure was sufficiently high foruse in the power cylinders of the engine, the engine compressor can beclutchably disengaged or air pumped by the compressor(s) can be bypassedback to the inlet of the compressor(s) so that no compression work wouldbe required of the compressor. A relief valve 60 prevents excess buildup of pressure in the air reservoir. A valve 61 (being in thisarrangement, a reversible one-way valve) allows air from the reservoirto be transferred to the manifold when the pressure in the reservoir 59is higher than in the transfer manifold 58, if the air is needed. In thecase of engine constructions having compression cylinders, eachcompression cylinder of the engine can also be deactivated during thisreserve air operation time by shutting off the admission valve so thatno net work would be done by the compressor(s) until themanifold-reservoir pressure dropped below operating levels. Severalsystems of deactivating cylinder valves are described in the art and/orhave been mentioned previously.

In an alternate arrangement, the compressor 57A is eliminated and theair storage tank 59 is used to store excess air compressed by thecompressor cylinders of the engine during braking and downhill travel.In this case, the valve 61 is a two-way valve and a blocking valve 70 isplaced in the manifold 58 between the compressor cylinder(s) 66, 67 andthe working cylinders 62-65. During downhill travel or during braking,the blocking valve 70 between compressor and working cylinders is,preferably, closed, power cylinders 62-65 are deactivated, and thetwo-way valve at 61 is utilized in order to divert the air compressed bythe compressor cylinder(s) into storage tank 59.

When it is desired to operate the engine normally, the blocking valve 70between the compressor and the expander cylinders is opened and thetwo-way valve 61 is closed During reserve air operation, both theblocking valve 70 and the two-way valve 61 are opened. If desired, thecompressor cylinder(s) 66, 67 are deactivated while in the reserve airoperation mode, as described earlier. Also, a Jacob brake (a prior artretarder brake) could supply compressed air to the air reservoir tank.

Operating the engine on reserve air supply would improve the meaneffective pressure (mep) of the engine for 20 percent improvement inpower and efficiency, while reducing polluting emissions, during thetime the engine was operating on the reserve air.

This feature would produce additional savings in energy especially inheavy traffic or in hilly country. For example, an engine producing 100horsepower uses 12.7 pounds of air per minute. Therefore, if energy ofbraking were stored in the compressed air in the economizer reservoir59, a ten or fifteen minute supply of compressed air can be accumulatedand stored during stops and down hill travel. When the reservoirpressure drops below the desired level for efficient operation, asolenoid (not shown) is used to reactivate the compression cylindervalves and they (with the supercharger, when needed) will begin tocompress the air charge needed by the engine.

Using the air reservoir 59, the engine needs no compression build-up forstarting and as soon as the shaft was rotated far enough to open theintake valve, the compressed air and fuel would enter and be ignited for“instant” starting. Furthermore, the compressed air could be used torotate the engine for this means of starting by opening intake valvesearlier than usual to the expander cylinders to begin rotation andfiring as is common in large diesel engines, thus eliminating the needfor a starter motor. Alternatively, the compressed air could be used tocharge a “hydrostarter” to crank the engine as is common on someheavy-duty diesel engines.

In an alternate, and still preferred embodiment, the reserve air inreservoir 59 is additionally used to “motor” the engine to allow avehicle such as a bus to pull away from a stop and operate fuelless for30-60 seconds or more, which is the time that greatest pollution occursin bus or stop-and-go delivery vehicle operation.

Remotely Compressed Air Embodiments

Referring now to FIG. 34, there is seen a schematic representation of anengine 100 in accordance with an alternate embodiment of the presentinvention for externally providing charge-air for marine, locomotive,stationary, or electric power generating engines, or any engineapplications of this invention, constant or variable load and speed,which have adequate electric power or waste or “bleed” air available. InFIG. 34, a remote electric air compressor 35 preferably with one or moreintercooled compression stages, preferably supplies temperatureconditioned charge-air (both high and low pressure, if needed) for oneor more engines of this invention. The charge-air, conditioned intemperature and pressure, is supplied directly to manifolds 13 and 14 byconduit 15AE from compressor 35. The engine intake conduit 9 of, forexample, FIG. 4, or low-pressure conduits 32 of other engines of thisinvention receive air from the atmosphere or alternatively receives lowpressure air from a low pressure conduit 15BE from compressor 35.

An alternate arrangement, also depicted in FIG. 34, for providingcombustion charge-air for any of the engines 100 of the presentinvention is to provide charge-air from conduit 15AR which supplieswaste or “bleed” air produced in industrial processes. The air issupplied either at 1 or 2 pressure levels. The lower pressure, ifneeded, preferably is supplied by dropping the pressure from the mainincoming waste air conduit 15AR with a pressure regulator valve (25 aleading to low-pressure conduit 15BR). The arrangement is similar to thearrangement of conduits 15-A, 15-B and valve 25 in, for example, FIG. 5,with conduit 15-A representing the supply conduit 15AR from the wasteair supply, and with conduit 15-B representing conduit 15BR in FIG. 34.

The use of remotely compressed air, either waste air or from compressor35, eliminates the engines compressors 1, 2 intercoolers 10, 11, 12,certain conduits and valves 3, 4, 5, 6 of the charge-air supplyequipment, providing the air has been conditioned during or after thecompression process (and prior to introduction to the manifolds 13, 14).Thus, the equipment of the engine 100 of the various embodiments shownthroughout the various drawing figures of the engine 100 embodiments ofthis invention, is preferably eliminated up to those points designatedby dashed lines A, B and C throughout the various drawings. Thecharge-air from either of the aforementioned remote sources ispreferably introduced into the engines near the manifolds 13 and 14 and,in the appropriate embodiments, the low air pressure from the remotesources is introduced at conduit 32, as shown in FIG. 34.

In the remotely charged engines, the fuel can be carbureted prior tocompression, can be throttle-body injected, port-injected, or directlycylinder injected.

Regarding Pollution Control

Referring now to FIG. 2 and FIG. 4-C there is shown a method of furtherreducing polluting emissions in any of the engine embodiments of thisinvention which includes re-burning a portion of the exhausted gaseswhen and if required. In the 4-stroke engines of FIG. 1-FIG. 3 and inthe 2-stroke engines herein depicted having a single air intake, theexhaust outlet conduit(s) 18 have a shunt conduit 202 (refer to FIG. 2)leading from a port 206 in the side of exhaust conduit 18 to a port 204in the side of intake conduit 8. A proportioning valve 201 is situatedat the intake port 204 and is arranged to selectively restrict the flowof fresh air into conduit 8, while at the same time opening the port 204to the exhaust conduit to selectively allow entry of exhaust gases tothe intake conduit 8. This valve is variable and mechanically,electrically or vacuum solenoid operated and preferably controlled by anengine control module (ECM) or control 144 in FIG. 35 and FIG. 36. Thisallows the re-burning of a portion of the exhausted gases, the amount ofpercentages thereof being adjusted by the engine control module inresponse to various sensors, such as an oxygen sensor, placed instrategic positions in the engine. Exhausted gases passing throughconduit 202 can be cooled by either optional cooling fins 202 a or bypassing through an optional intercooler (not shown) before reaching theair intake conduit 8.

With reference to FIG. 4C, in engines having only one atmospheric intakeconduit but having different air paths and conduits, such as conduits15-A and 15-C of FIG. 4B, a shunt conduit 202′ leading from the exhaustconduit 18 is divided into two shunt conduit portions 203 a, 203 b, eachwith a proportioning valve 209 a, 209 b operating so as to selectivelyadmit exhausted gases to either or both of intake valve 16-B (throughconduit 9 and eventually conduit 15-C) or to intake valve 16-A (by wayof conduit 8 and conduit 15-A). Each proportioning valve 209 a, 209 bwould allow either a portion or none of the exhausted gases to enter itsrespective port, meanwhile restricting entrance of fresh air ifnecessary. The exhausted gases can be cooled by optionally arrangingfins 202 a on conduit 202′ and/or 203 a, 203 b and 203 c or by passingthe exhaust through an optional intercooler (not shown) before the gasesare introduced into the air intake(s) of the engine.

Alternatively, as shown in phantom on FIG. 4C, one shunt portion 203 ais diverted (shown as 203 c) directly to conduit 15-C and provided therewith a proportioning valve 209 c.

In the engines of FIG. 4 and FIG. 7 having dual atmospheric air intakes8, 9, an arrangement similar to that shown in FIG. 4C is utilized, itbeing understood, however, that conduit 8 is open to the atmosphere.

In any engines having dual air intake conduits or dual air paths aportion of exhausted gases can be introduced in any amount necessary, infrom one to three points and controlled preferably by an engine controlmodule (ECM) for better management of combustion and emissionscharacteristics.

This re-burn feature is of particular importance with diesel fueloperation.

Constant Load and Speed Engines

Whereas the preponderance of the foregoing specification describesembodiments and representative engines of the present invention whichare optimized for vehicular (marine, truck, bus, automobile, tank, trainand plane) duty cycles and describe systems and methods for varyingpower, torque and speed, the present invention finds useful applicationfor obtaining high power and torque while maintaining optimum fueleconomy and low polluting emissions in less complex engines, such as,for example, constant load and speed engines. FIG. 35 and FIG. 36 depictalternate embodiments of the present invention which embodiments arerepresentative of constant load and speed engines (e.g., for electricpower generation and in other stationary or industrial engineapplications, e.g., for pumps and compressors) outfitted in accordancewith the principles of the present invention.

The Engine of 100 System of FIG. 35

Referring now to FIG. 35 there is shown is a schematic presentation ofan engine which represents any of the 4-stroke or 2-stroke engines ofthe present invention outfitted for constant load and speed operation.The basic components of the engine 100, such as compressors 1, 2 andoptional intercoolers 10, 11, 12 (shown in phantom) and their necessaryassociated conduits are, preferably, designed for optimum operatingparameters having only the basic components. The various controls,shutter valves, air bypass valves and their associated bypass conduitssuch as those in previously described embodiments, are preferablyeliminated in order to reduce weight, cost and complexity of operation.In FIG. 35, the engine 100 is shown as outfitted with a first ancillarycompressor 1 and a second ancillary compressor 2, optional intercoolers10, 11, 12 (shown in phantom) and interconnecting conduits, alloperating as would be understood with reference to the previous detaileddescriptions and operating with two stages of pre-compression of thecharge-air, intercooled or adiabatically compressed.

FIG. 35 shows a preferred setup for power generation with any of theengines of this invention. The power output shaft 20 of the engine 100is coupled schematically by line 140 to power input shaft 20″ ofgenerator 141 which has electric power output lines 142. As the shaft 20of the engine 100 rotates the shaft 20″ of generator 141, the amount ofelectric power produced by generator 141 is detected by sensor 143 andrelayed to control unit and governor 144 which contains various relaysand integrated circuits to quantify the power output and to sendmessages by line 145 to fuel/air control (not shown) on fuel line 148and throttle 56, and/or by line 149 to spark control to advance orretard the spark in spark-ignited engines and/or to send messagesthrough lines 146 and 146 b for engines having fuel injection systems,e.g. for natural gas, gasoline or diesel fuel, or to fuel/air controls,all in order to control the fuel input, speed and output of engine 100and hence the output of generator 141. Control unit 144 also sendssignals to control the proportioning valve 201, shown in FIG. 4 and toproportioning valves 209 a, 209 b, 209 c shown in FIG. 2 to control theamount, if any, of exhaust recirculated by these valves for re-burn inany engine of this invention utilizing this feature. Further explanationof the components and operation with the engine 100 of the presentinvention is deemed unnecessary as it would be understood by thoseskilled in the art having reference to the present disclosure.

The optional intercoolers 10, 11, 12 (shown in phantom) are preferablyused for gaseous or gasoline fueled engines and are preferablyeliminated or reduced in number or cooling capacity in thecompression-ignited engine, this being made possible by low peakpressures and temperatures in the engines of this invention.

Referring now to FIG. 36 there is shown an engine illustrated as a2-stroke engine but representing any of the engines of the presentinvention, 2-stroke or 4-stroke, which is coupled schematically by line140 with an electric generator 141. The engine and arrangements aresimilar in structure and operation as that shown and described for theengine of FIG. 35 with the exception that engine of FIG. 36, operatingas either 2-stroke or 4-stroke cycle engine 100, has only a single stageof pre-compression, optionally intercooled by intercoolers 11, 12 (shownin phantom), of the charge air. As with the engine of FIG. 35,intercoolers 11, 12 are preferably eliminated or reduced in coolingcapacity in compression-ignited versions of the engine 100 of thisinvention. Also, as with the engine 100 of FIG. 35, the governor, andother controls and the operation of the engine and generator would beunderstood by those skilled in the art having reference to the presentdisclosure.

It will be seen by the foregoing description of a plurality ofembodiments of the present invention, that the advantages sought fromthe present invention are common to all embodiments.

While there have been herein described approved embodiments of thisinvention, it will be understood that many and various changes andmodifications in form, arrangement of parts and details of constructionthereof may be made without departing from the spirit of the inventionand that all such changes and modifications as fall within the scope ofthe appended claims are contemplated as a part of this invention.

While the embodiments of the present invention which have been disclosedherein are the preferred forms, other embodiments of the presentinvention will suggest themselves to persons skilled in the art in viewof this disclosure. Therefore, it will be understood that variations andmodifications can be effected within the spirit and scope of theinvention and that the scope of the present invention should only belimited by the claims below. Furthermore, the equivalents of allmeans-or-step-plus-function elements in the claims below are intended toinclude any structure, material, or acts for performing the function asspecifically claimed and as would be understood by persons skilled inthe art of this disclosure, without suggesting that any of thestructure, material, or acts are more obvious by virtue of theirassociation with other elements.

1-24. (canceled)
 25. A method of operating an internal combustion engineincluding at least one cylinder and a piston slidable in the cylinder,the method comprising: supplying pressurized air from an intake manifoldto an air intake port of a chamber in the cylinder; selectivelyoperating an air intake valve to open the air intake port to allowpressurized air to flow between the chamber and the intake manifoldsubstantially during a majority portion of a compression stroke of thepiston; and operably controlling a fuel supply system to inject fuelinto the chamber after the intake valve is closed.
 26. The method ofclaim 25, wherein said selectively operating includes operating avariable intake valve closing mechanism to keep the intake valve open.27. The method of claim 26, wherein the variable intake valve closingmechanism is operated electronically.
 28. The method of claim 25,wherein the selective operation of the air intake valve is based on atleast one engine condition.
 29. The method of claim 25, wherein saidselectively operating includes operating the intake valve to remain openfor a portion of a second half of the compression stroke of the piston.30. The method of claim 25, wherein said operably controlling a fuelsupply system includes operating a fuel injector assemblyelectronically.
 31. The method of claim 25, wherein the pressurized airis cooled before being supplied to the air intake port.
 32. The methodof claim 25, wherein at or after the intake valve is closed a secondarycharge of pressurized air is injected into the chamber.
 33. The methodof claim 32, wherein the secondary charge is injected through a secondair port.
 34. The method of claim 32, wherein the secondary charge iscooled prior to injection.
 35. A method of operating an internalcombustion engine including at least one cylinder and a piston slidablein the cylinder, the method comprising: imparting rotational movement toa first turbine and a first compressor of a first turbocharger withexhaust air flowing from an exhaust port of the cylinder; impartingrotational movement to a second compressor; compressing air drawn fromatmosphere with the first compressor; compressing air received from thefirst compressor with the second compressor; supplying pressurized airfrom the second compressor to an air intake port of a chamber in thecylinder via an intake manifold; controllably operating a fuel supplysystem to inject fuel directly into the chamber; and selectivelyoperating an air intake valve to open the air intake port to allowpressurized air to flow between the chamber and the intake manifoldduring a portion of a compression stroke of the piston, wherein fuel isinjected during a combustion stroke.
 36. The method of claim 35, whereinfuel injection begins during the compression stroke.
 37. The method ofclaim 35, wherein said selectively operating includes operating avariable intake valve closing mechanism to interrupt cyclical movementof the intake valve.
 38. The method of claim 35, wherein the selectiveoperation of the air intake valve is based on at least one enginecondition.
 39. The method of claim 35, wherein said selectivelyoperating includes operating the intake valve to remain open for aportion of a second half of the compression stroke of the piston. 40.The method of claim 35, wherein said controllably operating a fuelsupply system includes operating a fuel injector assemblyelectronically.
 41. The method of claim 35, wherein the air is cooledprior to supplying it to the air intake port.
 42. The method of claim35, wherein at or after the intake valve is closed a secondary charge ofpressurized air is injected into the chamber.
 43. The method of claim42, wherein at least part of the secondary charge is injected throughthe air intake port.
 44. The method of claim 42, wherein at least a partof the secondary charge is injected through a second air port.
 45. Themethod of claim 42, wherein the secondary charge is cooled prior toinjection.
 46. An internal combustion engine, comprising: a blockdefining at least one cylinder; a head connected with said block, saidhead having an air intake port and an exhaust port; a piston slidable ineach cylinder; an air intake valve controllably movable to open andclose the air intake port; a first turbocharger including a firstturbine coupled with a first compressor, the first turbine being influid communication with the exhaust port, the first compressor being influid communication with the air intake port; a second compressor beingin fluid communication with atmosphere and the first compressor; a fuelsupply system operable to controllably inject fuel into the chamber; anda first controller configured to selectively operate the air intakevalve to remain open during a portion of a compression stroke of thepiston, and a second controller configured to inject fuel into thechamber during an combustion stroke.
 47. The engine of claim 46, whereinthe controller is configured to operate the intake valve to remain openfor a portion of a second half of the compression stroke of the piston.48. The engine of claim 46, wherein the fuel supply system includes afuel injector assembly.
 49. The engine of claim 46, including means forcooling the air compressed by the second compressor.
 50. The engine ofclaim 49, including means for cooling the air compressed by the firstcompressor.
 51. An internal combustion engine, comprising: a blockdefining at least one cylinder; a head connected with said block, saidhead having an air intake port and an exhaust port; a piston slidable ineach cylinder; an air intake valve assembly connectable with a camassembly to controllably move an intake valve to open and close the airintake port; a first turbocharger including a first turbine coupled witha first compressor, the first turbine being in fluid communication withthe exhaust port and an exhaust duct, the first compressor being influid communication with the air intake port; a second compressor, thesecond compressor being in fluid communication with atmosphere and thefirst compressor; a fuel supply system operable to controllably injectfuel into the chamber; and a variable intake valve mechanism connectablewith said air intake valve.
 52. The engine of claim 51, wherein saidvariable valve mechanism is actuated electronically.
 53. The engine ofclaim 51, further including an air cooler between at least one of saidfirst compressor and said second compressor.
 54. The engine of claim 51,further including a second air intake port controlled by a second airintake valve.
 55. The engine of claim 54, including a controllerconfigured to open the second air intake valve at a point which is at orafter the end of said portion of the compression stroke and before theend of the compression stroke.
 56. The engine of claim 54, wherein thesecond air intake port is in fluid communication with the firstcompressor.
 57. A method of controlling an internal combustion enginehaving a variable compression ratio, said engine having a block defininga cylinder, a piston slidable in said cylinder, a head connected withsaid block, said piston, said cylinder, and said head defining achamber, the method comprising: pressurizing air; supplying said air toan intake manifold of the engine; maintaining fluid communicationbetween said chamber and the intake manifold during a portion of anintake stroke and through a predetermined portion of a compressionstroke; and supplying a pressurized fuel directly to the chamber duringa portion of a combustion stroke.
 58. The method of claim 57, furtherincluding supplying the pressurized fuel during a portion of thecompression stroke.
 59. The method of claim 58, wherein supplying thepressurized fuel includes supplying a pilot injection at a predeterminedcrank angle before a main injection.
 60. The method of claim 59, whereinsaid main injection begins during the compression stroke.
 61. The methodof claim 57, wherein said predetermined portion of the compressionstroke is at least a majority of the compression stroke.
 62. The methodof claim 57, wherein said pressurizing includes a first stage ofpressurization and a second stage of pressurization.
 63. The method ofclaim 62, further including cooling air between said first stage ofpressurization and said second stage of pressurization.
 64. The methodof claim 57, further including cooling the pressurized air.
 65. Themethod of claim 57, wherein pressurized air is supplied to the chamberin two charges.
 66. The method of claim 65, wherein the primary chargeis supplied to the chamber through a port controlled by an intake valve.67. The method of claim 66, wherein the secondary charge is injectedinto the chamber during the compression stroke, at or after the intakevalve is closed.
 68. The method of claim 67, wherein the secondarycharge is injected through a second port.
 69. A method of controlling aninternal combustion engine having a variable compression ratio, saidengine having a block defining a cylinder, a piston slidable in saidcylinder, a head connected with said block, said piston, said cylinder,and said head defining a chamber, the method comprising: pressurizingair to a ratio of at least 4:1 with respect to atmospheric pressure;supplying the pressurized air to an intake manifold of the engine;maintaining fluid communication between the chamber and the intakemanifold during an intake stroke and a majority of a compression stroke;and supplying a fuel to the chamber during at least a portion of theremaining compression stroke.
 70. The method of claim 69, wherein saidmajority is at least 90 degrees crank angle after bottom dead center.71. The method of claim 69, wherein said supplying fuel includesinjecting a first portion of fuel a predetermined period prior toinjecting a second portion of fuel.
 72. The method of claim 71, whereinsaid injecting the second portion of fuel begins during the compressionstroke and terminates during a combustion stroke.
 73. The method ofclaim 71, further including cooling the air prior to supplying the airto the chamber.
 74. A method of operating an internal combustion engineincluding at least one cylinder and a piston slidable in the cylinder,the method comprising: supplying a mixture of pressurized air andrecirculated exhaust gas from an intake manifold to an air intake portof a chamber in the cylinder; selectively operating an air intake valveto open the air intake port to allow the pressurized air and exhaust gasmixture to flow between the chamber and the intake manifoldsubstantially during a majority portion of a compression stroke of thepiston; and operably controlling a fuel supply system to inject fuelinto the chamber after the intake valve is closed.
 75. The method ofclaim 74, wherein said selectively operating includes operating avariable intake valve closing mechanism to keep the intake valve open.76. The method of claim 74, wherein the selective operation of the airintake valve is based on at least one engine condition.
 77. The methodof claim 74, wherein said selectively operating includes operating theintake valve to remain open for a portion of a second half of thecompression stroke of the piston.
 78. The method of claim 74, furtherincluding injecting at least a portion of the fuel during a portion ofthe compression stroke.
 79. The method of claim 78, wherein injecting atleast a portion of the fuel includes supplying a pilot injection at apredetermined crank angle before a main injection.
 80. The method ofclaim 79, wherein said main injection begins during the compressionstroke.
 81. The method of claim 74, wherein supplying a mixture ofpressurized air and recirculated exhaust gas includes controllablyproviding a quantity of exhaust gas from an exhaust gas recirculationsystem.
 82. The method of claim 74, wherein the mixture of pressurizedair and recirculated exhaust gas is cooled before being supplied to theair intake port.
 83. The method of claim 74, wherein at or after theintake valve is closed a secondary charge of a mixture of pressurizedair and recirculated exhaust gas is injected into the chamber.
 84. Themethod of claim 83, wherein the secondary charge is injected through asecond air port.
 85. The method of claim 83, wherein the secondarycharge is cooled prior to injection.
 86. A variable compression ratiointernal combustion engine, comprising: an engine block defining atleast one cylinder; a head connected with said engine block, includingan air intake port, and an exhaust port; a piston slidable in eachcylinder; a chamber being defined by said head, said piston, and saidcylinder; an air intake valve controllably movable to open and close theair intake port; an air supply system including at least oneturbocharger fluidly connected to the air intake port; an exhaust gasrecirculation system operable to controllably provide a portion ofexhaust gas from the exhaust port to the air supply system; a fuelsupply system operable to controllably inject fuel into the chamber at aselected timing; a variable intake valve closing mechanism configured tokeep the intake valve open by selective operation of the variable intakevalve closing mechanism; and a controller configured to operate theintake valve to remain open for a portion of a second half of acompression stroke.
 87. The engine of claim 86, including a second airintake valve port, a second air intake valve controllably movable toopen and close the second air intake port, and a controller operatingthe second air intake valve.
 88. The engine of claim 87, wherein thesecond air intake valve is operated mechanically, electrically, or byvacuum.
 89. The engine of claim 88, wherein the controller operating thesecond air intake valve is configured to open the second air intakevalve at a point which is at or after the end of said portion of thesecond half of the compression stroke and before the end of the secondhalf of the compression stroke.
 90. A method of controlling an internalcombustion engine having a variable compression ratio, said enginehaving a block defining a cylinder, a piston slidable in said cylinder,a head connected with said block, said piston, said cylinder, and saidhead defining a chamber, the method comprising: pressurizing a mixtureof air and recirculated exhaust gas; supplying said air and exhaust gasmixture to an intake manifold of the engine; maintaining fluidcommunication between said chamber and the intake manifold during aportion of an intake stroke and through a predetermined portion of acompression stroke; and supplying a pressurized fuel directly to thechamber during a portion of a combustion stroke.
 91. The method of claim90, further including supplying the pressurized fuel during a portion ofthe compression stroke.
 92. The method of claim 91, wherein supplyingthe pressurized fuel includes supplying a pilot injection at apredetermined crank angle before a main injection.
 93. The method ofclaim 92, wherein said main injection begins during the compressionstroke.
 94. The method of claim 90, wherein said predetermined portionof the compression stroke is at least a majority of the compressionstroke.
 95. The method of claim 90, further including cooling thepressurized air and exhaust gas mixture.
 96. The method of claim 90,wherein a pressurized mixture of air and recirculated exhaust gas issupplied to the chamber in two charges.
 97. The method of claim 96,wherein the primary charge is supplied to the chamber through a portcontrolled by an intake valve.
 98. The method of claim 97, wherein thesecondary charge is injected into the chamber during the compressionstroke, at or after the intake valve is closed.
 99. The method of claim98, wherein the secondary charge is injected through a second port.